Architecture and processes for computer learning and understanding

ABSTRACT

An architecture and processes enable computer learning and developing an understanding of arbitrary natural language text through collaboration with humans in the context of joint problem solving. The architecture ingests the text and then syntactically and semantically processes the text to infer an initial understanding of the text. The initial understanding is captured in a story model of semantic and frame structures. The story model is then tested through computer generated questions that are posed to humans through interactive dialog sessions. The knowledge gleaned from the humans is used to update the story model as well as the computing system&#39;s current world model of understanding. The process is repeated for multiple stories over time, enabling the computing system to grow in knowledge and thereby understand stories of increasingly higher reading comprehension levels.

RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 15/192,796 filed Jun. 24, 2016, entitled“Architecture and Processes for Computer Learning and Understanding”,which is incorporated by reference.

BACKGROUND

The world has long dreamed of robots, machines, and computers that areartificially intelligent. From Hal in Arthur C. Clarke's Space Odysseyseries and Rosie the maid in the Jetsons cartoon series to the shipboardcomputer in the Star Trek series and R2D2 and C3PO in the Star Warssaga, we have been fascinated by machines that can inherently learn,understand, and think.

While this makes for very good entertainment and may hold aspirationalgoals for future generations of machines, the problems associated withartificial intelligence and building intelligent machines are verycomplex. For instance, no system exists today that can satisfactorilyengage in an open dialog with humans over arbitrary text, much less asystem that can independently “learn” from such interactions and explainjustified answers to complex questions.

There has been progress in this space. Well-known systems like IBM'sWatson enjoyed success on the TV game show Jeopardy and Apple's Siri hascertainly made it easier to find music and locations on Apple products.But these systems merely apply massive data, large training sets,shallow linguistic techniques, and machine learning techniques to thetask of automatic question answering. These systems lack deepunderstanding. More recent work on the Reading Comprehension taskremains focused on shallow statistical approaches with narrowanswer-based metrics rather than requirements for logical understandingand fluent explanation. Still today, however, no computer system canautonomously read, build, and communicate a logical understanding andexplanation of even an arbitrary 2nd-grade text.

Accordingly, there is an ongoing need for smarter machines that canlearn and understand.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Theuse of the same reference numbers in different figures indicates similaror identical items or features.

FIG. 1 illustrates an architecture and environment in which computingmachines engage with humans through dialog to learn and understandarbitrary text, such as that found in stories.

FIGS. 2A and 2B present a flow diagram of a process for learning anddeveloping an understanding through human interaction that may beimplemented by the architecture of FIG. 1.

FIG. 3 is a flow diagram of a process for teaching people by allowingthe people to engage in a dialog with a computing system around a topicthat is discussed in texts.

FIG. 4 illustrates an example implementation of select components in thelearning and understanding architecture of FIG. 1, and demonstrates howcertain processes and data may flow among the components.

FIG. 5 is a block diagram of a computing system and illustrates selectmodules executed by the architecture of FIG. 1 to enable a computingsystem to read, build, and communicate a logical understanding ofarbitrary text.

FIG. 6 is a flow diagram of a process for learning and understandingtexts that may be implemented by the architectural components of FIG. 4.

FIG. 7 is a block diagram of one example implementation of a storyparsing engine employed by the architecture of FIG. 1. FIG. 7illustrates one implementation of select components that may be used tosyntactically process a text string, such as a story, to producelinguistic analysis results.

FIG. 8 is a flow diagram of a process for syntactically processing textstrings, such as sentences, in a story.

FIG. 9 is a block diagram of one example implementation of a knowledgeintegration engine employed by the architecture of FIG. 1. FIG. 9illustrates select components that may be used to semantically processthe linguistic analysis results of the story.

FIG. 10 shows an example set of generative semantic primitive structuresthat can be composed to express ranges of meaning for a correspondingtext string (e.g., sentence).

FIG. 11 illustrates an example story, an example episode, and examplesemantic structures to demonstrate how an alignment module of theknowledge integration engine of FIG. 9 aligns frame semantics with anevolving story model to improve understanding of the story.

FIG. 12 is a flow diagram of a process for inferring semanticinformation in order to provide a deeper understanding of the story.

FIG. 13 is a block diagram of one example implementation of a knowledgeinduction engine found in the architecture of FIG. 1. FIG. 13illustrates select components that may be implemented to generateresources to aid in the inference of semantic information of the story.

FIG. 14 is a flow diagram of a process for providing probable candidatesfor senses and relations of words/phrases in the story to assist wheninferring semantic information about the story.

FIG. 15 is a block diagram of one example implementation of a beliefrepresentation and reasoning framework found in the architecture ofFIG. 1. FIG. 15 illustrates select components in the framework that maybe used to support operation of the architecture, including a knowledgerepresentation language and inference and learning mechanisms forcontextual differentiation and semantic primitives.

FIG. 16 is a block diagram of one example implementation of a dialogengine employed in the architecture of FIG. 1. FIG. 16 illustratesselect components in the dialog engine that generate user questions tochallenge or validate the system's current understanding of the story,and receive user responses for updating the system's understanding.

FIG. 17 shows an example of a dependency structure used by the dialogengine to generate appropriate questions to pose to one or more humanusers.

FIG. 18 is a flow diagram of a process for generating questions tosubmit to human users to verify and inform the system's currentunderstanding of the story as currently reflected in the semanticstructures and frames.

FIG. 19 shows a screen rendering of a dialog user interface presented ona user's device and seen by the user during a dialog session between thecomputing system and the human user.

FIG. 20 shows a second screen rendering of the dialog user interfacepresented on the user's device following the screen rendering of FIG. 19to illustrate a next question in the dialog session.

FIG. 21 shows a third screen rendering of the dialog user interfacepresented on the user's device following the second screen rendering ofFIG. 20 to illustrate yet another next question in the dialog session.

FIG. 22 is a block diagram with diagrammatic illustrations to show animplementation of a distributed dialog mechanism for distributing thesame or different questions to multiple human users in parallel.

FIG. 23 is a diagrammatic illustration of a first example distributeddialog session involving multiple users.

FIG. 24 is a diagrammatic illustration of a second example distributeddialog session involving multiple users.

FIG. 25 is a flow diagram showing a process for distributing questionsduring dialog sessions across multiple users.

FIG. 26 is a block diagram that illustrates the story model and how thedata structures contained in the story model evolve over time as aresult of the syntactic processing, semantic processing, and humaninteraction.

FIG. 27 is a flow diagram showing a process for growing computerunderstanding over time through processing and inferring increasinglymore difficult natural language stories and human interaction.

FIG. 28 is a diagrammatic illustration showing how knowledge, embodiedas semantic structures in a current world model, grows over time as morestories of increasing difficulty are subjected to syntactic processing,semantic processing, and human evaluation through dialog.

FIG. 29 shows an example set of visualizations that illustrates thedynamic process of incrementally formulating a network of probabilisticbeliefs and iteratively refining its global logical consistency.

DETAILED DESCRIPTION

This disclosure describes an architecture and processes for computerlearning and understanding. The architecture enables learning anddeveloping an understanding of arbitrary text through collaboration withhumans. This collaboration may be in the context of joint problemsolving or where the humans are used to teach the system or help thesystem understand the text it is reading. An architecture that canindependently acquire and transform knowledge from text into a form thatallows the system to reason, evolve, and meaningfully dialog wouldchange the world by greatly accelerating access to task-relevantknowledge and aiding in human research, learning, discovery, and problemsolving.

The computing architecture addresses the problem of deep naturallanguage understanding in which a computer system can autonomously read,build, and communicate a logical understanding and explanation of abroad range of natural language text. Much of what is needed for deepunderstanding is not explicitly present in the text (or in any text) butis instead implicit and learned through interacting with the world orthrough interactive dialog with humans. The processes described hereininclude engaging in dialog with humans in an interactive problem-solvingtask, such as reading comprehension, such that the computing systemiteratively learns to consistently, accurately, and independently assignintended meaning (validated by the interaction) to increasingly complexlanguage.

Deep natural language understanding is difficult because language itselfis hard. Language is infinitely composable, as there are many ways tosay the same thing and subtle differences in meaning exist. Forinstance, the word “touchdown” may refer to an airplane landing or to ascore in American football. Someone can be “mad about you” or “mad atyou”, which have two entirely different meanings. Imagine being able toengage in a conversation with a computer along the following script:

-   -   Human: Hello, I have a question.    -   Computer: Hi. How can I help?    -   Human: I'd like to discuss an article on the role of stem cells        in organ regeneration, both from a technical perspective and        from an ethical perspective.    -   Computer: Ok. This article suggests that stem cells can be very        effective. The technology works because stems cells contain . .        . open questions remain regarding . . . .    -   Human: Why do stem cells gravitate to the area of injury?        Computer: By “why”, you probably mean “how”. Is that true? If        so, the stem cells travel to and collect in the area of injury        using a chemical messaging system where . . . .        While perhaps such dialog is reasonable between two humans, this        sort of conversation is difficult for computers due to the many        levels of complexity introduced by imprecise language. There is        pervasive ambiguity in word senses, grammar, and intention.        Moreover, meaning is often implicit, where important information        is not stated and background information is assumed.

To further illustrate this point, consider the following short story:

-   -   The bat was flying toward him    -   Billy ran as fast as he could.    -   He made it home safe!        Depending upon the setting or background, there is more than one        way to understand this story. Read the story once with the word        “bat” meaning a flying mammal. Then, read it again and let the        word “bat” mean a baseball bat.

As humans, our knowledge and experiences also help us discern meaningfrom a story that may not be there in the text itself. As anotherexample, aspects of the architecture and processes below are describedwith reference to a simple 1st grade story named “Enzo and Zoe”, asfollows:

-   -   Enzo and Zoe were running a race. Enzo fell. He hurt his knee.        Zoe looked back. Zoe wanted to win. If she kept running she        would win. Zoe stopped. She ran back.    -   She helped Enzo up.        Consider simple questions like: What was Zoe looking at? What        did Zoe stop? Where did she run back to? Did Zoe win? What was        the weather? How old are Enzo and Zoe? Computing machines do not        usually start with the requisite experiences and knowledge to        fill in the blanks, and hence the processes described herein        enable the computing machines to formulate and articulate        questions for human engagement to gain this learning for a        richer understanding of the story.

Accordingly, the architecture described herein has a computing systemthat learns how to understand what it reads by collaborating, usingnatural language dialog, with humans to answer questions about a giventext, such as a story. The story may be accompanied by a number ofreading-comprehension questions. The system creates a semanticrepresentation of the story, which can be used, among other things, foranswering the reading comprehension questions.

The computing system first performs a linguistic analysis of the story,producing linguistic analysis results, such as a grammatical parse,predicate-argument structure, entity type assignment, and co-referenceanalysis. Using this linguistic analysis, the computing system creates asemantic representation of the story, in which the meaning of the storyis expressed in terms of generative semantic primitives (GSPs). GSPs area small set of structures that express basic facts about the world, suchas time, space, logic, number, change, cause, association, belief,perception, representation, and intention. GSPs can be composed torepresent a very wide range of meaning of natural language.

The computing system maintains and continuously updates a current worldmodel that contains its beliefs about what is true about the world. Thecurrent world model can be made of a collection of frames, where eachframe is a collection of propositions, such as GSPs, that are likely tobe true in some common context. For example, in the Enzo and Zoe story,frame structures may provide what generally occurs during a race. Thecomputing system constructs the story model drawing upon the knowledgein its current world model and on knowledge induced automatically fromlarge language corpora.

After the initial story model is built, the computing system tests thestory model through dialog with humans who have also read the story.This process may involve going through a reading comprehension exercisetogether, answering questions, and providing valid explanations. Thehuman dialog enables the computer system to discover additional implicitsemantics and background knowledge implicit in the story and uses thisimplicit knowledge to understand the story and future new stories. Humanresponses may be used to update the story model and adjust the computingsystem's selection of certain understandings. After revisions to themodel, the new understanding may further be tested through additionaldialog with humans.

In this manner, through dialog with humans, the computing system learnsover time to answer questions on successively more difficult readingcomprehension texts and demonstrates its ability to understand what itread by answering questions and by explaining why those answers arecorrect. For example, the system may start at a kindergarten level andwork up through higher grade levels. In some applications, the systemmay engage in a dialog with students who are also at the appropriategrade level for the text. The computer system generates and asksquestions to humans whose answers are subsequently used by the computersystem to learn how to map language into a logical model that representsits understanding.

In addition, the computer system may be configured to teach peoplethrough the interactive process. The system helps a human student builda logical model of what they are reading and learn to think criticallyby evaluating the system's understanding and by logically validating thesystem's answers, to ultimately arrive at a mutual understanding of thegiven story. The system learns and teaches analogical reasoning bygenerating analogies connecting story elements to other analogicalcontent that the computer system detects on background corpora and byasking the students to consider and validate those analogies. Throughmultiple such interactions, the students learn how to question,critique, explore, and extend their own knowledge, and the computersystem learns to consistently, accurately, and independently assignintended meaning (validated by the interaction) to increasingly complexlanguage.

In some situations, the computing system may further engage in dialogwith other computing systems in addition to human interaction. Forinstance, a first computing system may have gained an understanding of astory that the second computing system has not yet encountered. Thefirst and second computing systems may be able to engage in dialog overthe story so that the first computing system essentially teaches thesecond computing system. In this manner, as computer systems evolveseparately over time to develop expertise in different domains bylearning and understanding texts in those domains, the computer systemscan learn from each other to integrate the other system's knowledge. Thedialog between computer systems may be at a very different level, suchas communicating their respective semantic representations.

This architecture employs techniques from artificial intelligence, suchas knowledge representation and machine learning. In addition, itemploys techniques from natural language processing, such as, syntacticparsing, predicate argument structure, entity type assignment,co-reference analysis, and statistical techniques such as distributionalsemantics (e.g. latent semantic analysis, random indexing and topicmodeling).

Illustrative Architectural Environment

FIG. 1 illustrates an example architecture 100 in which machines, suchas computing systems, can engage with humans through dialog to learn andunderstand arbitrary natural language, such as that found in stories.For discussion purposes, the architecture is described in part in anexemplary environment of education where the computing system interactswith students of various levels for purposes of learning from themand/or teaching them by answering questions that the students ask.However, the architecture may be implemented in essentially anyenvironment and is not intended to be limited to education.

The architecture 100 includes a learning and understanding computingsystem 102 that is configured to ingest and analyze arbitrary naturallanguage and to learn and understand the meaning and sense of words andconcepts through collaborative interactions with humans. The humancollaboration may be done in the context of joint problem solving orwhere humans are used to teach or help the system understand the text itis reading. The learning and understanding computing system 102 may behosted on one or more servers 104(1), 104(2), . . . , 104(S), which haveprocessing and storage capabilities to ingest natural language inputthat may be in the form of arbitrary text strings, such as stories106(1), . . . , 106(T). The servers 104(1)-(S) process the naturallanguage input and engage with humans through user interfaces to improvemutual understanding of the natural language input for both the humansand the computing system. The servers 104(1)-(S) may be embodied in anynumber of ways, including as a single server, a cluster of servers, aserver farm or data center, and so forth, although other serverarchitectures (e.g., a mainframe architecture) may also be used.

In the illustrated implementation, the stories 106(1)-(T) are shownbeing input into the learning and understanding computing system 102.Generally, the stories may originate in any modality (speech, text, OCR,etc.) and are ultimately transformed into a digital formatrepresentation of the text (e.g., ASCII) for processing by the computingsystem 102. The stories may be accompanied by a number ofreading-comprehension questions. The stories may be stored by thecomputing system 102 and used by the system 102 to gain a deeperunderstanding of language. In this example, two stories are shown: a“Ben and Ava” story 106(1) and an “Enzo and Zoe” story 106(T). The Enzoand Zoe story 106(T) is provided above. Similarly, the Ben and Ava story106(1) is also a short story suitable for a younger student, as follows:

-   -   Ava walked in.    -   Ben showed Ava to a table.    -   Ava sat down.    -   Ben gave Ava a menu.    -   Ava ordered spaghetti.    -   Ben brought the food to Ava.    -   Ava ate and left.

According to the architecture 100, the computing system 102 shares thestories 106(1)-(T) with humans and engages in a dialog with people attimes to test the system's understanding of the stories. The learningand computing system 102 builds an initial model, which contains asemantic representation of the story to represent an initialunderstanding of the story. This first model is referred to herein asthe “story model” and described below in more detail. Generally, theinitial story model expresses the initial understanding in terms of datastructures that include syntax elements and/or sets of generativesemantic primitives (GSPs). Generative semantic primitives are a smallset of structures that express basic facts about the world and that canbe composed to represent the full range of meaning of natural language.For instance, for the sentence, “Ben brought the food to Ava”, thesyntax elements may be identifying “brought” as the verb and thesemantic primitives may include facts about the entities in thesentence, such as Ben causing an action that results in the food beinglocated near Ava or Ben's intention that Ava possess the food. The GSPscan be used, among other things, for answering reading comprehensionquestions.

Understanding language is more about what is unsaid and part of humanexperience than what is explicit in the written word. Typically, thebest interpretation of a natural language statement is the one that“makes the most sense” with respect to our knowledge about the world.The computing system 102 maintains and continuously updates anothermodel that contains beliefs about what is true about the world. Thissecond model is referred to herein as the “current world model” anddescribed below in more detail. The current world model is composed of acollection of frames, where each frame is a collection of propositions,such as GSPs, that are likely to be true in some common context. Thecomputing system 102 constructs an initial story model, drawing upon theknowledge in the current world model and on knowledge inducedautomatically from other sources, such as large language corpora.

After the initial story model is constructed, the learning andunderstanding computing system 102 may engage in a dialog with users whohave also read the story. The computing system 102 forms one or moreuser questions to pose to humans to test this initial understanding ofthe story. For example, the computing system 102 may generate questionsin cases where the story model is known to be incomplete, where thesystem does not have high confidence in its semantic representation, orwhere there are reading comprehension questions that cannot beconfidently answered. The system may ask questions to validate itsunderstanding or to acquire missing knowledge. For example, the userquestions may offer other possible sets of generative semanticprimitives to challenge whether the generative semantic primitives inthe initial story model convey an accurate meaning of the story. Theuser questions are provided in natural language transformed from thegenerative semantic primitives and sent to human users for their input.The users' responses to the questions is returned to the system 102 andused to augment the current world model and to modify or produce a newiteration of the story model that represents a new and enhancedunderstanding of the story. The new model expresses the newunderstanding as data structures that associate a different set ofgenerative semantic primitives that may further be assembled into framestructures that provide even more meaning. This process can be repeatedmultiple times until the computing system 102 has worked through thevarious scenarios and its understanding of the story aligns with how thehuman users would understand the story. The updated current world modelis retained for use in processing other natural language stories thatmight be ingested in the future. The individual story models may also bestored, to be recalled later if necessary. As the computing system goesthrough multiple user interactions on multiple stories, the currentworld model is incrementally enriched in each interaction, and thesystem learns to consistently, accurately, and independently determinesemantic representations for natural language text. The system can readprogressively more difficult stories, documents, and other texts overtime and engage humans to learn and understand increasingly moredifficult subject matter. As a result, the system continues to build andgrow the current world model 138 with new GSPs and new frames, as wellas other resources used in the system.

With reference again to FIG. 1, the computing system 102 may interactwith many human users as part of the dialog process, and these users mayhave different purposes for engaging with the system. For discussionpurposes, two groups of human users are illustrated, including humanstudents 110(1), 110(2), . . . , 110(L), who are illustrated asbelonging to a human student population 112, and human collaborators114(1), . . . , 114(C), who belong to a human-based collaborationcrowdsourcing network 116. The students 110(1)-(L) interact with thecomputing system 102 to learn as much from the computing system 102 asthe computing system learns from them. The students and the computingsystem 102 engage in joint problem solving tasks as they work through astory 106, thereby learning aspects from each through the process. Thestudents 110(1)-(L) may be of any age, reading level, or essentially anydemographic. For discussion purposes, two of the students 110 include agrammar student 110(1), such as a first grade student, and an adult110(2), such as a college student or professional. In some applications,the computing system 102 may engage in a dialog with students who are atthe appropriate grade level for the text.

The human collaborators 114(1)-(C) are engaged by the computing system102 primarily to test the system's understanding of text strings, suchas those found in the stories 106(1)-(T). The human collaborators114(1)-(C) may be formal collaborators, or untrained people who simplyanswer questions posed by the computing system 102. In oneimplementation, the collaborators 114 may be part of an organizedcrowdsourcing network 116, such as the Mechanical Turk™ crowdsourcingplatform from Amazon. Use of crowd interactions allows collaborativeaspects of the architecture 100 to scale, enabling the computing systemto learn more at a faster pace.

Both the students 110(1)-(L) and the human collaborators 114(1)-(C) maybe distributed, have no formal relationship with one another, and merelyinteract with the learning and understanding computing system 102 usingtheir own electronic devices. In some implementations, the system 102processes the story (particularly longer stories) into different partsand distributes different user questions for the different parts todifferent students or collaborators, thereby allowing the system tolearn about words and concepts in parallel and more quickly assimilatethe story.

The students 110(1)-(L) may interact with the learning and understandingcomputing system 102 in many ways, including directly with the system102 or through user-based electronic devices 118(1), 118(2), . . . ,118(D) (collectively, devices 118) that communicate with the system 102via a network 120. The network 120 is representative of any one orcombination of multiple different types of networks, such as theInternet, cable networks, wireless networks, and wired networks. Thestudent devices 118 have processing, storage, network and display/audiocapabilities that enable the students 110(1)-(L) to interact with thesystem 102. The devices 118 can be essentially any type of computingdevice, including for example, a computer 118(1), a multifunctioncommunication device 118(2), and a portable computer 118(D). Apart fromthose illustrated, other types of electronic devices may be used, suchas portable digital assistants (PDAs), cellular telephones, portablemedia players, tablet computers, netbooks, notebooks, desktop computers,set-top boxes, entertainment devices, cable boxes, gaming systems, andthe like.

The students 110 may interact with the learning and understandingcomputing system 102 through different or multiple modalities, includingtext, audio, and/or visual. As shown in FIG. 1, the story 106(T) about“Enzo and Zoe” may be depicted on a display of the student device 118(1)for reading by one of the students, such as the adult student 110(2).

Similarly, the student 110(1) has read the “Ben and Ava” story 106(1)and is now discussing the story with the learning and understandingcomputing system 102, as shown by a dialog user interface 122 presentedon the student's device 118(D). The student 110(1) may have read thestory on the same screen earlier, or listened to the story via atext-to-speech converter that outputs an audio representation of thestory over a speaker. During the story, or after its completion, thestudent 110(1) may ask questions about the story by typingquestions/comments into the user interface 122 or by speaking to thedevice 118(D) to verbally ask questions or make comments. In FIG. 1, thestudent 110(1) asks a verbal question “Why did Ben give Ava a menu?”depicted in the bubble 124. The computer 118(D) converts that audioquestion to a text format and presents the question in text format onthe UI 122. The computer 118(D) also sends the student question indigital form over the network 120 to the computing system 102, where thequestion is processed. The computing system 102 examines its currentunderstanding of the story and this particular element of the story andprovides a reply to the student. At this stage of the learninginteraction in this example, suppose the computing system 102 hasrecognized that the story includes actions such as Ben bringing a menuand food (spaghetti) to Ava. The computing system 102 identifies theseactions as possibly belonging to a frame that might involve a restaurantwhere Ben is the waiter and Ava is the customer. Accordingly, thelearning and understanding computing system 102 formulates a responsethat assumes the implication of a restaurant. In FIG. 1, an exemplaryresponse is sent to the device 118(D) and presented in the UI 122 as“The story mentions that Ben brought a menu and food to Ava. I believeBen and Ava are in a restaurant”. The computing system can further usethis interaction not only to teach the student 110(1) but also evaluatethe system's own understanding by adding a second statement, such as“Would you agree?”. If the system's responsive explanation is accurateto the student, the student can confirm that understanding, such as byanswering “yes” as shown in UI 122.

In this manner, the learning and understanding computing system 102 mayuse human interactions for the dual purposes of teaching the studentsand also learning from them to increase the computing machine'sunderstanding. From the student's perspective, the human and computerare learning together and solving problems. While this example assumesan elementary story, consider that this same interaction could play outover complex subjects, such as physics, life sciences, medicine, andmusic theory. The student 110 may be interested in learning a new topicthat he or she knows nothing about. While information can be foundthrough traditional searches, the student still needs to read and try tounderstand myriad results from such searches. In this architecture 100,the human student can interact with a computing system 102 that is orbecomes an expert on the topic through its deep understanding processesof various texts on the topic (e.g., white papers, research documents,etc.). The human student can ask the system questions in a naturaldialog and be taught about the topic through discussions about thetexts.

In another implementation, the architecture 100 allows for thecollaborators 114(1)-(C) to answer queries posed by the computing system102 as part of the process for learning to understand the stories106(1)-(T). Each of the collaborators 114(1)-(C) may use a computer orelectronic device of some kind, such as desktop computers, laptops,smart phones, PDAs, set top boxes, entertainment devices, gamingsystems, and the like. The learning and understanding computing system102 interacts with the collaborators 114(1)-(C) of the collaborationnetwork 116 for the primary purpose of improving understanding, and notfor instructing the collaborators. Accordingly, the computing system 102may present a different UI 126 when engaging the collaborators114(1)-(C) that poses questions to confirm or challenge the system'sunderstanding. In this example, the UI 126 shows a simple interaction inwhich the computing system 102 is attempting to better understand anexcerpt from the Ben and Ava story 106(1) regarding the sentence, “Benbrought the food to Ava.” In the UI 126, one dialog box 128(a)attributed to the computing system 102 (as represented by the butterflyicon) provides a user query:

-   -   Here is a sentence I'm trying to understand:        -   Ben brought the food to Ava.    -   What choice below uses the word “bring” most similarly to the        sentence above?        The computing system 102 also offers multiple options, and        provides those options in a second dialog box 128(b) that is        attributed to the collaborator's response (as represented by the        user icon). The system can rank the answer choices in the        generated question based on its internal confidence of each of        the choices. In this example, there are three options from which        the collaborator can choose.    -   1. Take something or somebody with oneself somewhere.    -   2. Cause to come into a particular state or condition.    -   3. Present or set forth legally.

One of the collaborators, such as collaborator 114(C), reviews thesystem-generated user query in box 128(a) and the choices in box 128(b),and then makes the selection by clicking on the option or speaking theanswer (e.g., option 1). The response is returned to the computingsystem 102 and used to improve its understanding of the story bypotentially modifying the story model and the set of semantic primitivesthat support the model. The responses may be further used for futureinterpretations of the words or phrases, such as the word “bring”, insimilar contexts that are read in the future.

As shown in FIG. 1, the learning and understanding computing system 102has multiple modules 130 that are stored and executed on the servers104(1)-(S). The modules 130 comprise programs, applications, datastructures, data stores, algorithms, and other processing logic andmemory to implement the computer learning and understanding processesdescribed herein. Select modules are shown in FIG. 1 to provide a highlevel overview, while additional modules and more detailed discussionsare provided below in this document with reference to later figures.

The learning and understanding modules 130 work together through jointinference and dialog with humans to produce a story model 132 thataccurately portrays a story, such as stories 106(1)-(T). The story model132 evolves over time from an early syntactic representation ofsentences in the story to data structures that contain instantiatedgenerative semantic primitives and frame structures composed of thesemantic structures to accurately convey higher levels of meaning aboutthe story.

The modules 130 include a story parsing engine 134 that receives thestory (e.g., stories 106(1)-(T)) and performs syntactic analysis ofsentences in the story to generate several linguistic analysis results.In one implementation, the linguistic analysis results include (1) asyntactic parse to provide sentence structure, (2) a predicate argumentstructure (PAS), (3) an entity type assignment that assigns a type toeach entity in the sentences; and (4) co-reference chains produced byco-reference analysis of the story. Potentially, multiple sets oflinguistic analysis results will be produced, because language is ingeneral ambiguous and it may not be possible to determine a singleanalysis that is certain to be correct. The linguistic analysis resultsand how they are produced are described below in more detail withreference to FIGS. 4 and 7.

A knowledge integration engine 136 receives as input the story and thelinguistic analysis results from the story parsing engine 134. Theknowledge integration engine 136 builds an initial, probabilisticsemantic representation of the story that makes sense with respect tothe system's current knowledge about the world, which is maintained in acurrent world model 138. The initial semantic representation forms thefirst version of the story model 132 that is then evolved over time bythe knowledge integration engine 136 through use of human interactionand previously acquired knowledge resources. In a story, information isoften left unsaid as it is assumed; unfortunately, this also can resultin ambiguous meanings. As will be described below in more detail, theknowledge integration engine 136 infers relevant semantic structuresthat effectively predict what is likely unsaid, so the system can formbetter knowledge models and ask more intelligent questions of the humanstudents or collaborators. When the story says, “Ben brought the food toAva”, the knowledge integration engine 136 assesses what information maybe missing, like: “Is Ben a waiter?”, “Is Ava in a restaurant?” and soon.

The knowledge integration engine 136 relies on the current world model138 stored in memory and a knowledge induction engine 140 to assist ininferring the relevant semantic structures. The current world model 138is a repository of all semantic knowledge the system has learned andbuilt up over time. The current world model 138 may include or be ableto reference a collection of generative semantic primitives which areinitially generic and uninstantiated. For instance, these generativesemantic primitives may include pre-formed structures for simpleconcepts like location, time, action, and experience that are initiallyuninstantiated with any additional information. The knowledgeintegration engine 136 identifies pertinent uninstantiated semanticprimitive structures from the current world model 138 and instantiatesthem with the words/phrases contained in the syntactic parses of thesentences in the story, such as mapping verbs (e.g., “go”, “bring”,“eat”, etc.) and entities (e.g. “Ben”, “Ava”, “menu”, “spaghetti”) intothe structures. The current world model 138 additionally contains acollection of frames. A frame is a probability distribution overpropositions (including but not limited to GSPs) in a particularcontext. A simple case is a set of propositions that are likely to betrue in a context, such as actions that typically occur in a particularplace (e.g., a restaurant). In one possible approach, the knowledgeintegration engine 136 builds and iteratively aligns the inferredsemantic structures and output of syntactic analysis to evolve the storymodel 132, preferring semantic structures that fit well with knownframes. The knowledge integration engine 136 essentially iterativelyaligns the story model 132 with knowledge embodied in the current worldmodel 138.

The knowledge integration engine 136 queries the knowledge inductionengine 140 to assist in making smart predictions. The knowledgeinduction engine 140 is configured to analyze large corpora and othersources offline and generate a resource repository, referred to hereinas “induced knowledge resources”, which captures information implied byor latent in the text of the story. The knowledge induction engine 140uses the induced knowledge resources to implement multiple tasks,including but not limited to word sense disambiguation, relationdetection, paraphrase generation, textual entailment, scene analysis,and missing text generation.

Among its various applied techniques, the knowledge induction engine 140disambiguates the word sense of a word (e.g., the word “ball” may be aformal dance or a piece of sports equipment). The induction engine 140can find/recognize paraphrases, where words and phrases can be rewrittenbut have roughly the same meaning (e.g., is “crowd erupted”approximately the same as “applause in the stands”?). The knowledgeinduction engine 140 may further detect relations among words or phrases(e.g., in the phrase “OPEC ramped up the price of oil”, the phrase“ramped up” has a relation of increasing an amount). The knowledgeinduction engine 140 may perform other forms of word and phrase analysisto detect and unlock other related knowledge. In each of these cases,the knowledge induction engine 140 returns to the knowledge integrationengine 136 a ranked list of candidates with associated inferenceprobabilities that are used by the knowledge integration engine 136 toselect proper word senses and build accurate semantic structures andframes that infuse meaning into the story model 132. More detaileddiscussion of the knowledge integration engine 136 and the knowledgeinduction engine 140 is provided below with references at least to FIGS.4, 9, and 13.

The dialog engine 142 takes the story model 132 and identifies areaswhere the semantic representation is incomplete or where the system haslow confidence in those representations. Confidence values may becalculated in various ways, and are task related and generally contextdependent. The dialog engine 142 generates dialog questions for thehuman population of students 110(1)-(L) and/or collaborators 114(1)-(C)to answer the questions with information they possess that will helpfill these gaps. The dialog engine 142 generates structured questions tochallenge or confirm the system's current understanding, as representedby the story model 132, and sends these questions over the network 120to one or more of the students 110(1)-(L) and/or one or more of thecollaborators 114(1)-(C). One example question is shown in UI 126, wherethe dialog engine 142 crafts a question seeking user feedback on how tointerpret the sentence “Ben brought the food to Ava.” Readingcomprehension questions may also be generated to help identify gapswhere the story model 132 and the current world model 138 areinsufficient to provide an answer to the question. The humanstudent/collaborator returns feedback over the network 120 to thecomputing system 102, where the results are collected by the dialogengine 142 and passed to the knowledge integration engine 136 foranalysis.

Based on the human-interaction results from the dialog engine 142, theknowledge integration engine 136 updates the current world model 138with modified or new semantic structures and further defined framestructures that represent new/revised concepts of the story. In thismanner, the system 102 continues to learn and gain deeper understandingof the language in the story. Moreover, the knowledge integration engine136 continues to iteratively refine the story model 132 against theupdated current world model 138. The knowledge integration engine 136continues to probe its understanding with humans with the help of thedialog engine 142 until a termination condition is reached, such as thesystem having sufficient confidence in its semantic representation ofthe story. In one approach, the knowledge integration engine 136 and thedialog engine 142 continue to iterate until a threshold confidence levelis reached that suggests the current understanding has a highprobability of accurately portraying the story. The threshold may be setand adjusted according to various applications and use contexts.

Confidence levels may be computed in a variety of ways depending uponthe goals of a given situation. The computing system 102 can be applied,for example, to many goals involving language understanding, such assummarizing a text or answering a question. A prerequisite for achievingsuch goals is that the computing system 102 be able to determine whichof its beliefs are true. In one implementation, the mechanism used bythe system for making this determination is to assign a confidence valueto each belief, where the confidence value represents how sure thecomputing system 102 is that the belief is true. The system 102iteratively adjusts the confidence values based on how well the system102 achieves its goal such that each iteration is better than the last.Eventually, this process finds a set of confidences for the beliefs thatmaximizes the system's performance on the goal for the current set ofbeliefs. This approach leads to two strategies the computing system 102can deploy to improve its performance on its goal and to decide when tostop improving.

First, the system can examine its beliefs independently from its goals.That is, the system can go from belief to belief seeking informationfrom the dialog engine 142 or the knowledge induction engine 140 tocorrect its confidence that the belief is true. The computing system 102can stop seeking more information either when it has exhausted its setof beliefs or when it finds that the confidence changes resulting fromnew information have dropped below a level of statistical significance.

Second, the computing system 102 can judge its ability to achieve a goalas adequate or inadequate and then act on that result. For example, ifthe system's question answering correctness accuracy were 60% and thesystem's goal is to achieve an accuracy of 70%, the system 102 wouldseek information from the dialog engine 142 or the knowledge inductionengine 140 to improve the confidence in its beliefs until that goal isachieved. Once that goal is achieved, the computing system 102 can couldstop improving. Alternatively, if desired, the computing system 102could continue to iterate further until the changes in its accuracy haddropped below a level of statistical significance. An advantage of thislatter approach over the former is that it also allows for an evaluationof the utility of adding new beliefs to the system vis-à-vis the goal athand. That is, if new beliefs improved the system's performance on thegoal, then the utility of the new beliefs is high. If the beliefs haveno or a negative impact, then the utility of the new beliefs is low.

Once the knowledge integration engine 136 is confident that the storymodel 132 represents a likely understanding of the story 106, the storymodel 132 may be stored and indexed for future retrieval and use. Theknowledge gained to produce the story model 132 is also captured in thecurrent world model 138. In this manner, the understanding developed foreach story may be kept for future consideration and perhaps even morerefinement as more information is learned. Moreover, as the system goesthrough multiple user interactions on multiple stories, the currentworld model 138 is incrementally enriched in each interaction. As morestories are read, the current world model 138 grows with more inferredframes and is capable of assisting in the understanding of increasinglymore complicated subject matter. More detailed discussion of the dialogengine 142 is provided below with references at least to FIGS. 4, 16,and 22.

In the illustrated implementation, the learning and understandingmodules 130 further include a belief representation and reasoningframework 144 which provides a facility for working with knowledgemodels as one way to implement the story model 132 and the current worldmodel 138. Knowledge models are formal, structured representations ofknowledge, which can be expressed in a knowledge representation language(KRL) consisting of “entities” and “propositions.” An entity representsa thing in the world, including things that are fictional, e.g.“Pegasus”, or abstract, e.g. “philosophy”. A proposition is a statementthat can be true or false. A proposition has a predicate (which is akind of entity) and a set of arguments, where each argument has a label(called a role) and a value that can either be entities or propositions.The same role can have multiple values. A belief is a proposition thatan agent (often, but not necessarily, the system itself) thinks is truewith some probability.

The framework 144 comprises functional components used by variousmodules in the system. The framework uses the knowledge representationlanguage and provides inference and learning mechanisms for “contextual”differentiation and generative semantic primitives, which are a smallset of structures that can be composed to represent the meaning ofnatural language texts. More particularly, the components of theframework 144 may include (1) a formal language to represent theentities and propositions, (2) common semantics components to provide aset of define proposition types that are expected to be frequently used,(3) a knowledge store to provide persistent storage of knowledge modelsand support queries over that knowledge, and (4) one or more reasoningengines that provide different reasoning capabilities over knowledgemodels. More detailed discussion of the belief representation andreasoning framework 144 is provided below with references at least toFIGS. 4 and 15.

FIG. 1 provides an overview of select modules 130 in the learning andunderstanding computing system 102. More detailed explanations andexamples are provided below beginning with reference to FIG. 4. Beforeproviding that more detailed explanation, however, high level processesimplemented by the architecture 100 of engaging students 110(1)-(L) andcollaborators 114(1)-(C) will be described with reference to FIGS. 2 and3.

Furthermore, FIG. 1 illustrates the example dialogs with humans beingconducted in English. However, it is noted that the architecture 100described herein is language agnostic and can be configured to interactwith humans in any language.

Illustrative General Operation

FIGS. 2A and 2B show a general process 200 implemented by thearchitecture 100 of FIG. 1 for learning and developing an understandingof language used in texts (e.g., stories) through human interaction. Theprocess 200 (and all subsequent processes described with reference toflow diagrams) is illustrated as a collection of blocks in a logicalflow graph, which represent a sequence of operations that can beimplemented in hardware, software, or a combination thereof (e.g., suchas that provided by servers 104(1)-(S)). In the context of software, theblocks represent computer-executable instructions that, when executed byone or more processors, perform the recited and referenced operations.Generally, computer-executable instructions include routines, programs,objects, components, data structures, and the like that performparticular functions or implement particular abstract data types. Whenexecuted by processors, the computing system is transformed into amachine specially configured to learn and gain understanding of textlanguage as presented in stories. The order in which the operations aredescribed is not intended to be construed as a limitation, and anynumber of the described blocks can be combined in any order and/or inparallel to implement the process or further separated into more blocksof more incremental steps.

For discussion purposes, the process 200 is described with reference tothe architecture 100, the computing system 102, and the user devices 114and 118 of FIG. 1. Further, the process 200 is shown in two columns togenerally depict operations performed by the computing system 102separately from operations performed by the user devices 114 and 118.

With reference to FIG. 2A, at 202, a story is received at the learningand understanding computing system 102. The story is formed of multipletext sentences, as exemplified by the short “Ben and Ava” story 106(1)and the short “Enzo and Zoe” story 106(T). The story is ingested in, orconverted to, a digital format by the system 102. The same story isreceived by a user device 114/118, at 204, and presented to the user forhim or her to read the story, at 206. The story may be displayed and/orconverted to an audio output for the user to consume. The story may beaccompanied by a number of reading-comprehension questions.

At 208, the computing system 102 generates a first or initial storymodel to represent a first understanding of the story. Generating thefirst story model involves a syntactic analysis (referred to as storyparsing), producing linguistic analysis results (e.g., syntactic parse,predicate-argument structure, entity type assignment, co-reference) foreach sentence, at 210. With reference to FIG. 1, the story parsingengine 134 is configured to perform this parsing operation. The parsingoperation produces a set of linguistic analysis results, including asyntactic parse to provide sentence structure, a predicate argumentstructure (PAS), entity type assignments, and co-reference chains. Theparsing operation and examples thereof are described in more detailbelow with reference to FIGS. 4-8.

Once the linguistic analysis results are produced, at 212, the computingsystem 102 infers a semantic structure as a representation of eachparsed sentence by semantically processing the syntactic representationof the parsed sentence. The knowledge integration engine 136 andknowledge induction engine 140 perform the tasks in support of this act212 of inferring a semantic structure. The resulting first story modelis expressed as knowledge data structures of entities and propositions,such as through an associated set of instantiated generative semanticprimitives and frame structures.

At 214, the system evaluates the story model with respect to the currentworld model. The system may identify areas where the story model doesnot contain a high-confidence semantic representation that fits wellwith the known frames in the current world model. The system may alsoidentify deficiencies in the story model where there are readingcomprehension questions that cannot be confidently answered. At 216, thecomputing system 102 generates one or more user questions to probe theuser's understanding of the story, and/or to improve, test, or challengethe system's understanding of the story. The user questions includeinquiries that offer other possible understandings based on differentsets of generative semantic primitives to challenge whether the initialinstantiated generative semantic primitives convey an accurate meaningof the story. The dialog engine 142 may be used to generate the userquestions.

At 218, the user questions are sent from the computer system 102 to theuser computing device 114/118 for presentation to the human user. At220, the questions are received and presented to the user, such as via aUI 126 in FIG. 1, or audibly output for the user to hear. At 222, theuser device captures the user responses, which may have been entered viathe UI or spoken. Since the user has read the story presented at 206,the user has the story context to answer the questions. The user relieson his or her knowledge, background, and experiences to answer thequestions, thereby potentially providing new information that can beadded to the current world model. The computing system may not have hadthis information previously or perhaps may not have fully appreciatedthe information that it did have. At 224, the user device sends the userresponses back to the computing system 102.

At 226, the user responses to the questions are received at thecomputing system 102. The interactions between the computing device 102and user devices 114/118 may involve sending multiple questions andreceiving multiple responses to adequately extract the knowledge fromthe human user.

With reference to FIG. 2B, at 228, a new story model is generated torepresent a new understanding of the story. As part of this operation,the user responses are used to update the current world model, at 230,and the original story model 132 is revised to align with the updatedcurrent world model 138, at 232. The new story model expresses its newunderstanding as a knowledge data structure of entities andpropositions, as represented by a new set of instantiated generativesemantic primitives and frame structures. The new set of instantiatedgenerative semantic primitives and frame structures are different,albeit maybe only slightly, than the first set of instantiatedgenerative semantic primitives and frame structures.

At 234, after formation of the new story model 132, that story model isevaluated against the updated current world model. Confidence scores arecalculated to determine how well the story model aligns with the currentworld model. Higher scores are given when a small number of frames matcha large number of beliefs extracted from the story. Furthermore, a setof frame alignments scores poorly if newly predicated beliefs arecontradictory with the system's other beliefs about the story. At 236,the confidence scores are compared to a threshold. If a terminationcondition has been reached, such as when the confidence scores satisfy apre-established threshold (i.e., the “yes” branch from 236), the storymodel 132 is output as an accurate understanding of the story, at 238.Conversely, if the termination condition is not reached, such as whenconfidence scores fail to satisfy the pre-established threshold (i.e.,the “no” branch from 236), the process 200 returns to generate a new setof user questions to further test the understanding of the new storymodel at 216 (FIG. 2A).

In the example of FIGS. 2A and 2B, the architecture 100 is described asengaging a human population to help the system learn and gain a deeperunderstanding of natural languages as represented in stories. Thecomputing system 100 engages users either in an ad hoc learningenvironment or in a more formal collaboration environment wherecollaborators are posed questions for the purposes of improving thesystem's knowledge. However, the architecture 100 may be used in aneducation environment to teach humans about certain topics that aredescribed in text-based works, while continuing to refine the system'sown knowledge base. One such example is described with reference to FIG.3.

FIG. 3 shows an exemplary process 300 for teaching people about a topicof interest by engaging in an interactive dialog around that topic. At302, a person uses his or her device 114/118 to begin a dialog sessionwith the computing system 102. The user may initiate the dialog sessionin any number of ways, including by asking a question, making astatement about a topic of interest, or referencing a text or article todiscuss. At 304, the computing system recognizes the implicit requestfor a dialog session and generates a transition response designed toengage the user on a particular topic and perhaps extract moreinformation from the user. The transition response may be one of manypossible pre-established and pre-stored transition statements (e.g.,“What can I help you with?”; “Can you tell me more about what you wantto know?”; “When you said ‘airplanes’, what types of airplanes interestyou?”; etc.). In some implementations, the system may use the sameprocess as FIGS. 2A and 2B to dialog with the user to discover the topicto be discussed. The system may have a frame designed to help a humanget started in learning a topic, and the system attempts to inferinformation about that frame. If a variable cannot be inferred, then thesystem would ask the human about it, leading with a general transitionquestion above.

At 306 and 308, the computing system and the user, via his or her userdevice, engage in a dialog session to define the topic. At 310, thecomputing system identifies one or more texts pertaining to the topic.The texts may be embodied in any number of forms, such as an article,white paper, product description, educational primer, book excerpts, andthe like. Once identified, at 312, the computing system builds aknowledge model about the topic from the text. As above, this mayinvolve parsing the text, at 314, and inferring semantic structuresrepresenting the text, at 316.

At this point, the computing system 102 is ready to discuss the topicwith the user. The system can generate a summary about all the relevantinformation it has read on the topic. At 320, the user may ask questionsvia device 114/118 about the topic. At 322, the computing system 102receives the questions and formulates computer-generated responses basedon the newly created topic model and the current world model. Theresponses may provide basic information that the system has a highconfidence that the current world model is accurate. Alternatively oradditionally, the response may be in the form of questions intended toreconcile differences between the knowledge model of the subject beingdiscussed and the current world model. The responses are sent to theuser device and presented to the user, at 324, for the user to learnfrom the responses. Through this interactive exchange, the computingsystem 102 teaches the user about the topic and further learns and gainsa deeper understanding of the text describing the topic through aligningthe knowledge model created based on the text and the current worldmodel.

At 326, the process 300 continues until the user indicates that he orshe has sufficiently learned the topic (i.e., the “yes” branch from326). If he or she is not finished (i.e., the “no” branch from 326), theuser may ask further questions on the topic at 320, or move onto a newtopic and restart the process at 302. If the user is finished (i.e., the“yes” branch from 326), the process 300 may be completed.

Illustrative System Design

FIG. 4 shows selected modules 130 that implement the learning andunderstanding architecture of FIG. 1. The modules 130 are shown beinghosted by the learning and understanding computing system 102. Themodules 130 include the ones introduced in FIG. 1, and additional datastores. FIG. 4 also illustrates data flows among the various modules todemonstrate the process workflow through the architecture as a computergenerated story model emerges through joint inferencing and dialog withhumans to understand language in a story.

As shown in FIG. 4, a natural language input, such as text, is ingestedby the learning and understanding computing system 102 and is alsoprovided to the user devices 114/118 associated with the humanstudents/collaborators. The text may be essentially any digital form ofwords, phrases, or sentences written or spoken in a natural language,and is illustrated in FIG. 4 as a story 106. The text may be presentedon the display screen of the users for reading or played audibly for theusers to listen.

The story parsing engine 134 is executed to analyze the subject text andproduce a set of linguistic analysis results. Among the linguisticanalysis results are a syntactic parse that provides informationpertaining to sentence structure. A syntactic parse is similar tosentence diagramming that students learn in grammar school, where verbs,nouns, and such are structurally related. The story parsing engine 134also determines the predicate argument structure (PAS) with aparser-neutral representation of predicates and their instantiatedarguments which serve as primitive beliefs on which other analysiscomponents operate. For instance, following the syntactic parse of thesentence, “Ben brought the food to Ava”, the PAS recognizes that “Ben”is the subject argument, “food” is the object argument, and “brought” orthe root form “bring” is the predicate (or verb predicate in this case).The story parsing engine 134 further assigns entity types to the variouswords/phrases in the sentence and derives co-reference chains ofwords/phrases that although are not identical, are referring to the samething

To illustrate the operation of the story parsing engine 134, considerthe following sample text:

-   -   Hot liquid rock is below the ground. Volcanoes are openings in        the ground where that liquid can come out. Sometimes, volcanoes        erupt. That means they explode. Smoke and hot liquid rock come        out of the volcano. The liquid is called lava. Mt. Vesuvius is a        famous volcano in Italy.        For the sentence “Smoke and hot liquid rock come out of the        volcano”, the story parsing engine 134 may form a PAS having the        root predicate of “come”, with “smoke” and “hot liquid rock” as        subject arguments. The engine further identifies “smoke”,        “rock”, and “volcano” as nouns, “hot” and “liquid” as adjectives        modifying the noun “rock” and further recognizes “and” as a        conjunction between subject nouns “smoke” and “rock”. The engine        134 also annotates words with entity types, such as annotating        “Mt. Vesuvius” as a mountain type and “Italy” as a country type.        The story parsing engine 134 may further recognize that the        terms “hot liquid rock”, “that liquid”, “hot liquid rock”,        “liquid”, and “lava” can all be co-referenced as referring to        the same thing.

The story parsing engine 134 outputs the linguistic analysis results,along with the story, to the knowledge integration engine 136. Thelinguistic analysis results may include the syntactic parse andpredicate argument structures, which together form a linguisticstructure, as well as the entity types and co-references of the story106.

A more detailed description of one implementation of the story parsingengine 134 is provided below with reference to FIGS. 7 and 8.

The knowledge integration engine 136 takes as input the story and thelinguistic analysis results to build an initial, probabilistic semanticrepresentation of the story model 132 that “makes sense” with respect tothe system's current knowledge about the world as contained in thecurrent world model 138. The knowledge integration engine 136 is a setof executable components that evolve the story model 132 over timethrough joint inference and human interaction to align the story model132 with the current world model 138. The knowledge integration engine136 is a configurable and highly flexible module composed of beliefgeneration components 402, constraint components 404, and a jointinference engine 406. The belief generation components 402 input a setof beliefs and output a probability distribution over new beliefs thatmay be true given the input beliefs. As discussed previously, a beliefis a proposition that the system or another agent thinks is true withsome probability. The constraint components 404 input a set of beliefsand output a score indicative of the probability that the set of beliefsis true. The joint inference engine 406 takes the output from the beliefgeneration components 402 and the constraint components 404 andcalculates the joint distribution over beliefs. This is used tocalculate the marginal probability of each belief, which is used toconstruct the story model. The joint inference engine 406 may beconfigured to produce conditional probabilities for possible beliefsbased on all beliefs as known at the time. In some contexts, the beliefgeneration components 402, the constraint components 404, and the jointinference engine 406 may be referred to generally as the joint inferencesystem.

The joint inference engine 406 can operate in a variety of ways. In oneimplementation, the joint inference engine proposes multiple possibleworlds, where each world has a set of beliefs that are considered true.The belief generation components 402 are iteratively run on the worlds,observing the beliefs that are true and proposing distributions over newbeliefs. New worlds are created by drawing beliefs from thoseprobability distributions. The constraint components 404 are run toevaluate the probability of worlds. When the process is finished, themarginal probability of a belief is the sum of the probability of theworlds in which it is true. Since the marginal probabilities may notcapture the relationships between probabilities of beliefs, the worldsmay be stored as part of the story model 132. A more detailedimplementation of possible belief generation components is provided withreference to FIG. 9.

With joint inference, the knowledge integration engine 136 combineslevels of interpretation. That is, the engine 136 interprets text atvarious levels of conceptual richness. Higher levels of interpretationare more powerful, but also more implicit and therefore harder to infer.In one implementation, the interpretation levels include a first or baselevel which is essentially the natural language text, perhaps expressedin a sequence of words (or sometimes generically called “tokens”). Thesecond or next interpretation level involves a linguistic analysis ofthe natural language text. This linguistic analysis may be performed toprovide a grammatical parse and statistical word similarity (e.g.,embeddings). This second level of interpretation is provided by thestory parsing engine 134.

The third level involves analysis of generative primitive semantics toprovide richer meaning in the form of spatial, temporal, and cognitivefacts about the text language. Generative semantic primitives (GSPs) maybe viewed as atomic building blocks of meaning, allowing for a moremeaningful interpretation of the language in the story. GSPs representbasic facts about the world, such as time, space, logic, number, change,cause, association, belief, perception, representation, and intention.GSPs may be instantiated and composed in countless ways to represent allof the machine's knowledge and experience. GSPs are expressed as KRLpropositions with a predicate and roles. A GSP is instantiated whenstory entities and other GSP propositions fill these KRL roles. Entitiesfrom text in the story (either mentioned explicitly or implied to existin a discourse context) may instantiate a role in the KRL propositioncorresponding to a GSP. Additionally, GSPs can be composed via nestingone GSP in a role of another GSP. This compositionality allows thesystem to express an unlimited number of facts about the meaning ofnatural language statements. In this way, a GSP structure provides acommon way to interpret the meaning or semantics of Ben taking some foodto Ava in the Ben and Ava story, regardless of how the sentence isactually penned. For instance, that meaning can be expressed in thefollowing similar, but non-identical ways: “Ben brought the food toAva”; “Ben took the food to Ava”; “Ben served the food to Ava”; “Benhanded Ava the food”; “Ava took the food from Ben”; “Ava acquired thefood from Ben”; “Ben gave Ava the food”; “Ava got the food from Ben”;and “Ben brought Ava the food”. Arbitrary instantiations of GSPs can betranslated to natural language, allowing for humans to interact directlywith the system's representation of a text without being exposed to theinternal representation of the GSPs.

The fourth and top level pertains to analysis of frame semantics whichprovides logical or common-sense knowledge scripts, thereby filling inmuch of what might be implicit in the story. A frame is a probabilitydistribution over propositions (such as GSPs) in a particular context. Asimple case is a set of propositions that are likely to be true in acontext, such as actions that typically occur in a particular place. Inthe Ben and Ava story, for example, a “restaurant” frame may provide theimplicit information that Ben and Ava are in a restaurant, therebyproviding a theme or context within which to better understand theexplicit language in the story. The restaurant frame applies because theexperiences described in the story match the experiences stored in thatframe. For instance, the restaurant frame might consist of GSPs for thefollowing sequence of actions that are likely to occur in the context ofa restaurant (here they are shown in a natural language representation,but in the actual frame they would be represented as GSPs):

-   -   Customer enters the restaurant    -   Customer sits at a table    -   Customer waits for the waiter to come    -   Waiter brings customer a menu    -   Customer picks the food that they want to have    -   Waiter brings the food to the customer    -   Customer eats the food    -   Waiter brings the bill    -   Customer pays the bill    -   Customer leaves the restaurant        The knowledge integration engine 136 makes use of such frames        when processing a story, such as applying the restaurant frame        to the understanding of the Ben and Ava story.

The knowledge integration engine 136 evolves the story model 132 bytaking the basic linguistic analysis results generated by the storyparsing engine 134 (i.e., second level interpretation) and theninferring meaning through use of generative semantic primitives (i.e.,third level interpretation) and frame semantics (i.e., fourth levelinterpretation).

As part of its operation, the knowledge integration engine 136 performsa frame inference process to infer both generative semantic primitivesand higher level frames. The frame inference process includes four mainaspects: frame retrieval, frame alignment, belief prediction, andevaluation. In frame retrieval, a subset of frames is identified fromthe current world model 138 that may be relevant to the system's currentbeliefs about the story. Frames can also be generated dynamically on thespot using statistical or rule-based techniques. Frame alignmentinvolves determining assignments of entities in the story to roles(variables) in the frame. Frame alignment is done using a variety ofmatching algorithms based on statistical and/or semantic techniques. Forexample, in one implementation, if the propositions are textualpropositions, the computing system 102 can use a statistical textsimilarity algorithm (e.g. Word2Vec) to align/match the propositions. Ifthe propositions are GSP-based containing typed entities and relations,the system can use a semantic matcher based on an ontology (e.g.,WordNet) to align/match the propositions. For example, Ben aligns towaiter and Ava aligns to customer. Following alignment, the knowledgeintegration engine 136 asserts beliefs predicted by frames, so that eachsemantic primitive structure that is in the frame but not mentioned inthe story is a possible inference. The engine 136 then produces a scorefor how well the set of frame alignments match the story. A higher scoreis given when a small number of frames match a large number of beliefsextracted from the story. Also, a set of frame alignments mayalternatively score poorly if beliefs predicted by frames arecontradictory with the system's other beliefs about the story.

Frame inference may occur at multiple levels of interpretation. At thesentential level, frame inference can be used to infer the GSPscorresponding to the linguistic structure of a sentence or clause. Inthis case, each frame contains a mixture of semantic primitivestructures and linguistic analysis results. As one exampleconfiguration, for each sentence in the story, the knowledge integrationengine 136 instantiates one or more GSP structures with information fromthe linguistic analysis results to produce GSP structure instances. Inthe Ben and Ava story, the engine 136 can instantiate an action GSPstructure instance by possibly filling a reifier role with the evententity referred to by the word “bring” (reifier: story/bring), the agentrole with the entity referred to by the word “Ben” (agent: story/Ben),and an after-state with a nested proposition relating the fact that Avapossesses the food. This nested proposition may have a possessor rolewith the entity referred to by the word “Ava” (possessor: story/Ava) anda possession role with the entity referred to by the word “food”(possession: story/food).

At the episodic level, frame inference can be used to determine whichsets of GSPs are likely to fit well together and what new inferences canbe made. For example, in the Ben and Ava story, the “restaurant frame”is a good fit with the GSPs for the actions mentioned in the story, e.g.“Ben brought Ava a menu”. If Ben is aligned with waiter and Ava isaligned with customer, new inferences can be made such as “Ben broughtthe bill” and “Ava paid the bill”.

As noted previously, frames are themselves propositions and as such canbe referenced by other, higher-level frames. For example, there may be aframe about eating in general, including the actions of chewing andswallowing, perhaps using a knife and fork, etc., and this entire framewould be included with some probability in the restaurant frame. Ingeneral, the frame inference process may iterate multiple times todiscover a hierarchy of frames that “explains” the story.

In one implementation, at a basic level, a general frame could becreated from a specific text by replacing occurrences of particularentities with their entity types (person, or customer and waiter). Theknowledge integration engine 136 may access a library of frames in thecurrent world model 138 and select one or more frames that exhibit ahigh probability of being relevant to the words/phrases in the story.For instance, in the Ben and Ava story, words such as “menu”, “food”,“table”, etc. may map to GSP structure instances like “(waiter) bringsfood to (customer)” and “(customer) has the food”. Such GSP structuresinstances may then be grouped to define roles in frames, where in thisexample, these GSP structure instances may be appropriate for framespertaining to the hospitality genre, such as a restaurant frame, a hotelframe, or a pub frame. These frames may be combined into an aggregate,more general hospitality service frame. Once selected, the knowledgeintegration engine 136 determines an alignment of entities in the storyto the conceptual roles in the frame (e.g., Ava is the customer and Benis the waiter) that would make the GSP structure instances in the framematch the GSP structure instances in the story model. Through thisconstruction and instantiation of the frame structure, the knowledgeintegration engine 136 aligns the frame with the linguistic componentsof the story. The instantiated frame structure provides a newunderstanding of the story, and may be returned to the current worldmodel 138 to increase the body of knowledge stored therein.

Over time, the knowledge integration engine 136 may be used to inducenew frames as well. Frame induction is a process by which, as the systemreads and understands more text, it creates new frames to add to thecurrent world model. As the system reads more texts and engages humansin dialog, the current world model 136 grows with the addition of newframes, thereby increasing its knowledge and ability to help understandmore sophisticated subject matters. In one implementation, at a basiclevel, a general frame could be created from a specific text byreplacing occurrences of particular entities with their entity types(person, or customer and waiter). A more detailed description of oneimplementation of the knowledge integration engine 136 is provided belowwith reference to FIGS. 9-12.

The knowledge integration engine 136 may further query the knowledgeinduction engine 140 to learn more about the words/phrases found in thestory. The knowledge induction engine 140 contains an executablecomponent that can run offline or separately from the other componentsto analyze large language corpora 410 and other sources. The knowledgeinduction engine 140 uses a variety of techniques to derive a number ofinduced knowledge resources, which capture information implied by orlatent in the text. The knowledge integration engine 136 maysubsequently query the repository 412 to perform tasks such as wordsense disambiguation, relation detection, paraphrase generation, textualentailment, scene analysis, and missing text generation.

A more detailed description of one implementation of the knowledgeinduction engine 140 is provided below with reference to FIGS. 13-14.

The learning and understanding modules 130 may further include a beliefrepresentation and reasoning framework 144, which is a set offoundational components used throughout the system 102 by all of thevarious modules 130. The framework 144 provides the knowledgerepresentation language and enables higher level functionality likeinference and learning mechanisms for contextual differentiation andsemantic primitives. The framework 144 also performs basic operationsthat allow the system 102 to store, index, retrieve, navigate, andmanipulate probabilistic propositions (or “beliefs”) over time. Theframework 144 provides the mechanisms to define the GSP structures andframes to represent natural language in the story model 132 and thecurrent world model 138. The framework 144 may also produceprobabilities that express how likely various semantic relations are fora suitable interpretation of the story sentence.

In one implementation, the story model 132 and the current world model138 are structured as knowledge models, which are formal, structuredrepresentations of knowledge formed of entities and propositions. Anentity is a thing, which may exist (e.g., “dog”, “cat”, “truck”, etc.)or may not actually exist (e.g., “Pegasus”, “Sherlock Holmes”). Anentity may also be an abstract concept (e.g., “animal”, “philosophy”,“action”, etc.). Entities can have names and are defined by all theinformation known about them. A proposition is a statement that can havea truth value. Every proposition has a predicate and a set of arguments,which may be entities or propositions. The story model 132 is aknowledge model that is intended to represent what is stated in aparticular piece of text (story) being read by the system. The currentworld model 138 is a knowledge model that is intended to representgeneral knowledge about what is true in the world.

In this implementation of knowledge models, the framework 144 is afacility for working with the knowledge models. The framework 144includes a formal language for representing entities and propositions, aset of defined proposition types that are expected to be frequentlyused, a persistent storage for knowledge models that may be queried foraccess to the knowledge, and a set of components that provide differentreasoning capabilities over knowledge models.

A more detailed description of one implementation of the framework 144is provided below with reference to FIG. 15.

The learning and understanding modules 130 may further include a dialogengine 142 to facilitate question-and-answer dialog sessions with humanusers to test or validate the system's understanding of the story asrepresented in the story model. The dialog engine 142 takes as input thestory model 132 and current world model 138, uses them as the basis togenerate questions for the user and/or to answer questions from theuser, and outputs an updated story model and an updated current worldmodel after incorporating knowledge obtained through user interaction.The dialog process also leverages other system components such as theknowledge integration engine 136 and the knowledge induction engine 140to help interpret user questions/responses and formulate systemquestions/responses. For example, in the Ben and Ava story, the systemmay not be able to discern at first that the food refers to thespaghetti, leaving part of a semantic structure unfilled. The dialogengine 142 can generate one or more questions to ask the user whetherthe food is likely to be the spaghetti.

In other cases, the system may not be confident of its currentassumptions. For instance, suppose the knowledge induction engine 140predicts that two senses of the word “bring” as used in the story yieldroughly the same probabilities of being correct. The knowledgeintegration engine 136 may choose one of the senses. Because the systemis not entirely confident of this choice, the dialog engine 142 may askquestions about the accuracy of this word sense choice in the particularsentence or story.

The dialog engine 142 may engage single users in linear dialog sessionsor distribute the questions to a larger group of users in parallel. Inthis distributed approach, for example, the dialog engine may logicallyseparate questions into different sets and ask different users thedifferent sets of questions. Distributed dialog sessions allow thecomputer system to scale across a crowd of users, and reduce latency ofthe learning process through parallelized interaction with multipleusers.

The questions may be presented to the user(s) in any number of ways andmodalities. The users consider the questions and provide responses. Thedialog engine 142 uses the responses to decide what follow-on questionsto ask the user. Additionally, the dialog engine 142 processes theresponses to update semantic structures and frames in the current worldmodel and the story model, thereby improving the system's understandingof the story.

The dialog sessions may be repeated until a termination condition ismet, such as when the knowledge integration engine 136 achieves asufficient confidence level in a semantic representation of the storythat fits well with the known frames in the current world model. In oneimplementation, the dialog engine 142 may be tasked to express theunderstanding to the user for final validation as to accuracy. Once thetermination condition is reached, the story model 132 may be stored andindexed for future use, and the updated current world model 138 isretained for use in processing other stories.

FIG. 5 shows one exemplary implementation of the architecture 100 inmore detail, with the learning and understanding system 102 beingimplemented on the servers 104(1)-(S) and the user devices beingimplemented as an electronic device 114/118. The servers 104(1)-(S)collectively provide processing capabilities 502 and memory 504. Thememory 504 may include volatile and nonvolatile memory, removable andnon-removable media implemented in any type or technology for storage ofinformation, such as computer-readable instructions, data structures,program modules, or other data. Such memory includes, but is not limitedto, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM,digital versatile disks (DVD) or other optical storage, magneticcassettes, magnetic tape, magnetic disk storage or other magneticstorage devices, RAID storage systems, or any other medium which can beused to store the desired information and which can be accessed by acomputing device.

Stored in the memory 504 are system datastores 506, which definemultiple databases for maintaining data structures, datasets, textstrings such as stories, language corpora, and the like. In thisexample, the datastores 506 include the story model 132, the currentworld model 138, the database of semantic primitives 408, the largelanguage corpora 410, the induced knowledge resource repository 412, andother possible datastores 508.

The learning and understanding modules 130 are shown embodied assoftware modules stored in the memory 504 and executable by theprocessor 502. The learning and understanding modules 130 include thestory parsing engine 134, the knowledge integration engine 136, theknowledge induction engine 140, the dialog engine 142, and the beliefrepresentation and reasoning framework 144. Each module may beseparately invoked and executed to process data pulled from one of thesystem datastores 506 or to produce output data that is stored back inone of the system datastores 506.

The servers 104(1)-(S) communicate with one or more collaborator devices114(1)-(C) and/or one or more student devices 118(1)-(D), as representedas device 114/118 in FIG. 5. The device 114/118 has a processor 510 andmemory 512 (e.g., volatile, non-volatile, etc.). An operating system514, a reader user interface (UI) 516, and a speech/text converter 518are stored in the memory 512 and executed by the processor 510. Theelectronic device 114/118 includes a display 520 to depict the reader UI516 so the human user can read the stories and interact with thecomputing system 102 during a dialog session in which the users askquestions of the computing system 102 and the computing system asksquestions of the users.

The device 114/118 may support other modes of interaction, includingpresenting the stories audibly by converting the text to speech in thespeech/text converter 518 and outputting the audio through a speaker522. The user may then listen to the story, rather than read it. Theuser may also verbalize questions and answers by speaking responses thatare captured by a microphone 524 and converted to text strings by thespeech/text converter 518. While screens, keyboards,speakers/microphones are discussed, the device may include essentiallyany other I/O device to facilitate interaction between the human and thecomputer system.

FIG. 6 shows an exemplary process 600 implemented by the architecture100, and more particularly, the learning and understanding modules 130of FIGS. 4 and 5, to ingest text-based stories, infer an understandingof those stories, and engage humans in dialog to test that understandingof the stories. At 602, the story (or text string) is received by thecomputing system. The same story is also shared with the user andpresented on the user device, at 604. For sake of discussion, supposethe story read by both the computing system and the user is the Ben andAva story 106(1).

At 606, the story is parsed to produce a syntactic representation of thestory. The syntactic parsing may be performed on sentences, clauseswithin a sentence, or other multi-word text strings. In the architecture100, the story parsing engine 134 performs the syntactic parse andoutputs linguistic analysis results that include a linguistic structureholding the words of the sentence that are tagged or annotated withsyntactic labels describing the words and a predicate argument structuredefining relationships amongst the words. The linguistic analysisresults may further include entity types assigned to words in thesentence and co-reference chains. In our story example, the syntacticparse may generate a linguistic structure that identifies the word“brought” as having a root form “bring”, which is the verb predicate inthe sentence. The word “Ben” is determined to be the subject argumentand the word “food” is the object argument. Further, “Ben” is typed as aperson and “food” is typed as nutrition (for example). Finally, thewords “food” and “spaghetti” may be assessed as belonging to a commonco-reference chain.

At 608, semantic structures and frames containing them are inferred torepresent possible interpretations of the story. In one implementation,the knowledge integration engine 136 infers the semantic structures bysemantically processing the linguistic analysis results received fromthe syntactic parse in view of pre-established background knowledge. Forinstance, the background knowledge may be embodied in part as pre-formeduninstantiated structures of generative semantic primitives stored inthe database 408 that provide common associations or relations forwords/phrases found in the parsed sentence. The uninstantiated GSPstructures are selected from the database and instantiated usingelements from the syntactically parsed sentence. The knowledgeintegration engine 136 may further select and instantiate frames thatare each composed of multiple instantiated GSP structure instances toprovide an even higher level of interpretation, thereby potentiallyenabling a deeper understanding.

Continuing the example of the Ben and Ava story, an uninstantiated GSPstructure corresponding to the action may be selected and instantiatedwith information from the syntactically parsed sentence. For example,the GSP structure's reifier role may be filled with the event entityreferred to by the word “bring” (reifier: story/bring), the agent rolewith the entity referred to by the word “Ben” (agent: story/Ben), and anafter-state with a nested proposition relating the fact that Avapossesses the food. This nested proposition is itself a GSPcorresponding to the concept of possession, and may have a possessorrole with the entity referred to by the word “Ava” (possessor:story/Ava) and a possession role with the entity referred to by the word“food” (possession: story/food). The generality of the GSP structures isdue to their compositionality, which relies in part on the ability ofthe system to nest one GSP structure within another. As evident fromthis example, the current linguistic interpretation of the sentence isenhanced to a deeper level of understanding by adding in likelyrelationships of who brought what to whom, and what is the state afterthis action. This additional semantic information provides a richerunderstanding.

As other GSP structures are instantiated for the sentences of the story,a frame inference process is performed, in which relevant frames areretrieved and aligned with the story. For instance, in the Ben and Avastory, a restaurant frame may be retrieved, and Ben may be aligned towaiter and Ava to customer. New beliefs are then asserted from theframe, for instance that Ben brought the bill and Ava paid the bill. Theset of frame alignments is evaluated such that a higher score is givenwhen a small number of frames match a large number of beliefs extractedfrom the story. Also, a set of frame alignments may alternatively scorepoorly if beliefs predicted by frames are contradictory with thesystem's other beliefs about the story.

At 610, as part of the inference operation, other semantic informationabout the words/phrases in the sentence may be produced to provide oneor more probable ways to interpret the words/phrases. For instance, inone approach, the knowledge integration engine 136 may query theknowledge induction engine 140 to provide such semantic information asword sense, paraphrases, relations, scene analysis, and so forth. Thegenerated results may be returned with associated probabilities so theknowledge integration engine 136 may choose the more likely candidatesto make more accurate inferences and the dialog engine 142 can eliminateuse of low probability candidates to avoid asking seemingly wrong orunintelligent questions.

In the Ben and Ava story, the knowledge induction engine 140 may performword sense disambiguation for the word “brought” or its root form“bring”. Through disambiguation, several possible senses of the word“bring” might be discovered, such as: (1) take something or somebodywith oneself somewhere; (2) cause to come into a particular state orcondition; or (3) present or set forth legally. Other analyses mayprovide other resources, such as the phrase “served the meal” may be aparaphrase of “brought the food”. The knowledge induction engine 140 mayfurther provide probabilities associated with these results to assist inselecting the appropriate one. The word “bring” may, for example, bemore likely associated with the first sense (i.e., take something orsomebody with oneself somewhere) as opposed to the third sense (i.e.,present or set forth legally) when appearing in the corpora.

At 612, the story is evaluated with respect to the frames retrieved fromthe current world model to discover areas where the story model does notcontain a high-confidence semantic representation that fits well withthe known frames in the current world model, or identify inferences withlow probabilities that should be validated by human users. In this way,possible gaps that might exist between what is currently known in thestory and what is represented in the instantiated frames may beascertained, revealing information that should or could be added to aGSP structure or frame. With respect to the Ben and Ava story, forexample, the alignment operation may discover that there are multiplesenses of “bring” (for the verb “brought” in the story) with sufficientlikelihood scores that raises a doubt as to which to choose. In thesesituations, consultation with humans can help remove the doubt.

At 614, one or more questions may be formulated to resolve the gaps orchallenge inferences. The questions, when asked of the user, areintended to evaluate how well the current semantic structures and framesrepresent the story, particularly in cases where the computer system isless confident of its current understanding. This operation may beperformed, for example, by the dialog engine 142 working in cooperationwith the knowledge integration engine 136. For instance, in the Ben andAva story, suppose the knowledge integration engine 136 initiallydetermines that the sentence “Ben brought the food to Ava” involves anaction semantic structure containing the verb “bring”. One question thatmight be formulated is to ask a person whether the verb “bring” shouldbe considered an action, and hence be associated with an action semanticstructure. That question might be crafted, for example, as “I think‘bring’ refers to an action, that something is different after the bringaction happens. Is that correct?” In other situations, there may be alack of clarity around a word sense. For instance, the knowledgeinduction engine 140, when queried, may inform the knowledge integrationengine 136 that the word “bring” has multiple senses, as noted above.Accordingly, the dialog engine 142 may formulate a question thatattempts to resolve this issue. One suitable question may be craftedlike the one shown in UI 126 in FIG. 1, as follows:

-   -   Here is a sentence I'm trying to understand:        -   Ben brought the food to Ava.    -   What choice below uses the word “bring” most similarly to the        sentence above?        -   1. Take something or somebody with oneself somewhere.        -   2. Cause to come into a particular state or condition.        -   3. Present or set forth legally.

At 616, a dialog session is opened with the user. During the session,the structured questions are submitted from the computing system 102 tothe user device 114/118, at 618. At 620, the questions are presented forconsumption by the human user (e.g., visually and audibly). The userexamines the questions and provides his or her input, which is capturedand returned to the computing system 102, at 622. For instance, the usermay review the question above, and decide that option 1 (i.e., takesomething or somebody with oneself somewhere) is the correct response.The user responses are received and processed by the computing systemfrom the user device, at 624.

At 626, one or more of the semantic structures and/or frames are revisedbased on the responses received from the human user to develop adifferent interpretation of the story. The story model may then berealigned with the revised semantic structures and frames (act 612), andnew questions generated (act 614) for another dialog session (act 616).

The process 600 may be continued until a sufficient confidence level iscomputed for the aligned story model. In one implementation, confidencescores are computed for instantiated semantic structures that providethe semantic representation of each word/phrase in the story. As each istested within the various semantic structures by engaging in dialog withthe user, the confidence scores tend to improve. At that point, thestory model 132 may be output as an accurate understanding of the story.It contains a full semantic representation of the story, and the systemcan index the story for future recall or use in understanding othertexts.

Illustrative Story Parsing Engine

FIG. 7 shows one implementation of the story parsing engine 134,illustrating select components that may be used to process a textstring, such as a story. The story parsing engine 134 is configured topropose multiple possible linguistic analysis results, and to pass thoseresults onto the knowledge integration engine, which calculates a jointdistribution over the results using joint inference. The story parsingengine 134 ingests a story 106 and passes a digital representation ofthe story 106 to a linguistic analyzer 702 for natural languageprocessing (NLP). The linguistic analyzer 702 receives the story 106 andbreaks the story into digestible segments, such as words, phrases,sentences, or other definable text-strings. The linguistic analyzer 702has a set of NLP components that perform various language analyses onthe text strings. A syntactic parser 704 identifies the parts of speechof words and the grammatical relationships between them in a sentence.In one implementation, the syntactic parser 704 is implemented in partby using the Stanford CoreNLP package for syntactic parsing.

In some implementations, the story engine 134 may employ a single parserwhich outputs multiple possible parses for a sentence or multipleparsers 706 to provide parsing diversity. A parse selector 708 may beused to choose or merge the parse results according to desiredapplications, with the goal to ultimately improve parse accuracy for thegiven applications. In other implementations, there may be no parseselector, but rather the multiple parse results will be passed to theknowledge integration engine 136, which will determine the confidence ineach parse result jointly with the confidence in the semantic and framestructures, as described below in more detail.

The linguistic analyzer 702 of the story parsing engine 134 alsoincludes a predicate argument structure (PAS) module 710 that produces aparser-neutral representation of predicates and their instantiatedarguments which serve as primitive beliefs on which other analysiscomponents operate. The PAS module 710 transforms a parser-specificrepresentation of grammatical relations to a common representation ofpredicates and arguments so that grammatical information produced bydifferent parsers can interoperate in the system. In the transformationprocess, the PAS module 710 also performs certain normalizationprocedures, such as changing passive voices into active, and simplifiesthe representation by removing certain grammatical relations that arenot central to processing of the sentences. For instance, following thesyntactic parse of the sentence “Ben brought the food to Ava” in thestory 106, the PAS module 710 recognizes that “brought” or its root form“bring” is the main predicate (verbal predicate in this case), and that“Ben” is the subject argument and “food” is the object argument. The PASmodule 710 tags or otherwise marks these words with the appropriatelabels. In one particular implementation, the PAS module 710 isconfigured on top of the syntactic parser 704; in other implementations,the syntactic parser 704 and PAS module 710 may be implemented as acommon executable module.

As shown in FIG. 7, the linguistic analyzer 702 outputs a set oflinguistic analysis results 712 that will be passed from the storyengine as an input to the knowledge integration engine 136. One part ofthe linguistic analysis results 712 is a linguistic structure 714produced by the syntactic parser 704 and the PAS module 710 of thelinguistic analyzer 702. The linguistic structure 714 is embodied as adata structure containing the words of the sentence, the syntacticlabels of the words, and PAS relationships amongst the words. The datastructure 714 is illustrated in FIG. 7 using a tree-like visualizationin which key words are represented as nodes and their relationshipsrepresented by interconnecting branches. Continuing the example sentence“Ben brought the food to Ava”, the word “bring” (i.e., the lemma form of“brought”) is shown as node 716 and identified as a verb predicate. Theword “Ben” is represented as node 718 and tagged as the subject argumentrelative to the verb predicate “bring”. The word “food” is representedas node 720 and marked as the object argument relative to the verbpredicate “bring”. The word “Ava” is represented by node 722 with arelationship to the verb predicate “bring” indicating that Ava is thetarget of the bring predicate.

The linguistic analyzer 702 further includes an entity assignment module724 to assign entity types to the various words in the sentence. Thetypes are predetermined categories from one or more applicableontologies. Essentially any semantic type can be defined, but commontypes might include person, country, location, furniture, sport, etc. Inour example, the entity assignment module 724 assigns a “person” type tothe word “Ben” and a “nutrition” type to the word “food”, as illustratedin the entity type data structure 726. In one implementation, the entityassignment module 724 may be implemented using the named entityrecognizer in the Stanford CoreNLP package, which is used toautomatically annotate entity types. Another implementation may involveuse of a word sense disambiguation component that assigns types based onthe WordNet hierarchy to the words in the sentence.

The linguistic analyzer 702 also has a co-reference module 728 thatidentifies co-references of words/phrases in the sentence. Co-referencesare words/phrases that, although not necessarily lexically identical,refer to the same real world entity. In this example, suppose the story106 had other sentences including the words “food”, “meal”, and“spaghetti”. The co-reference module 728 might identify thesewords/phrases as meaning the same thing, and produce a data structure730 that associates the words/phrases in some manner. The co-referencemodule 728 may identify entity co-references as well as eventco-references. The linguistic analysis results 712 are delivered to theknowledge integration engine 136, which is described in more detail withreference to FIG. 9.

In another implementation, as the linguistic analysis results 712 areintegrated into the story model, the joint inference engine 406 canfurther leverage downstream the linguistic analysis results tore-compute the likelihood of upstream results as they apply to naturallanguage processing (NLP) analysis. The story parsing engine 134considers higher level semantic information and world knowledge inscoring alternative parses that is derived from frame-level knowledgeinferred over a whole story. That is, the story parsing engine 134 canutilize the higher level downstream knowledge to re-compute thelikelihood of alternative parses. In addition, this ability todynamically re-compute likelihood strengthens over time as the systemaccumulates more knowledge in the current world model 138.

FIG. 8 shows an exemplary process 800 that is executed by the storyparsing engine 134 to syntactically process an incoming story. Theprocess 800 is described with reference to the system architecture 100and the story parsing engine 134 of FIGS. 1, 4, 5, and 7. At 802, a textstring is received. The text string may be part of a story andrepresentative of one or more natural language sentences in the story.At 804, the text string is linguistically analyzed. In one approach,this involves multiple sub-operations represented by acts 804(1)-(4).

At 804(1), the text string is syntactically analyzed to develop a syntaxrepresentation of the words in the sentences. With reference to FIG. 7,the linguistic analyzer 702 invokes one or more syntactic parsers 704 toparse the text string, thereby producing a linguistic structure 714 thatprovides grammar relationships amongst the words. At 804(2), a predicateargument structure (PAS) analysis is performed to transform the parserepresentation into a parser-neutral PAS representation. As oneapproach, the predicate argument structure module 710 tags or otherwisemarks certain words within the sentence as a predicate and one or morearguments. These designations are stored and reflected in the datahierarchy of the linguistic structure 714.

At 804(3), entity types from an appropriate ontology are assigned towords in the text string. Entity types are predefined (e.g., person,place, thing, etc.). The entity assignment module 724 identifiespossible entity types for each word in the text string based oncontextual and ontological information, and tags the word with theentity type. The entity assignments are maintained in a data structure726 that forms part of the linguistic analysis results.

At 804(4), any co-reference chains in the text string are alsodetermined. Whereas each sentence or logical text segment may have anassociated linguistic structure, co-reference chains are formed byexamining the whole story to find words/phrases that are refer to commonreal world entities. This act 804(4) may be performed, for example, bythe co-reference module 728 by examining the words and phrasesthroughout the text string and identifying words that form co-referencechains based on semantic and contextual information. Any discoveredco-references are stored in a data structure 730.

Together, the linguistic analyses at 804(1)-(4) produce a set oflinguistic analysis results 712 including the linguistic structure 714,the entity type structure 726, and the co-references structure 730. Itis further noted that in some implementations, linguistic analyzer 702may produce multiple linguistic analysis results for the same sentence.For instance, suppose the analyzer 702 is processing the sentence, “Thecat caught the mouse because it was clever.” When trying to characterizethe term “it” for syntax reasons or for co-reference chains, there maybe more than one answer because “it” may refer to the “cat” or to the“mouse.” At this stage, since there is not yet additional semanticknowledge, the story parsing engine may output both possibilities to beresolved downstream by the knowledge integration engine.

At 806, the linguistic analysis results 712 may be input to theknowledge integration engine 136. The linguistic analysis results 712may be incrementally outputted as completed or sent in batch to describethe entire story 106. The linguistic analysis results are subsequentlysemantically analyzed to produce an initial story model comprising a setof generative semantic primitives.

Illustrative Knowledge Integration Engine

FIG. 9 shows an exemplary implementation of the knowledge integrationengine 136, illustrating select components that may be used tosemantically process the linguistic analysis results 712 of the story106. The linguistic analysis results 712 are created by the storyparsing engine 134 from the ingested story and passed to the knowledgeintegration engine 136 (along with the story 106) to initially build astory model 132 representing the story. The knowledge integration engine136 builds the story model 132 as a probabilistic semanticrepresentation of the story that makes sense with respect to thesystem's current knowledge as captured in the current world model 138.

The knowledge integration engine 136 is a set of highly configurable andflexible executable components that evolve the story model 132 over timethrough joint inference and human interaction to develop the meaning ofthe story by aligning the story model 132 with the current world model138. The knowledge integration engine 136 infers relevant semanticstructures that take in the linguistic analysis results 712 of sentencesin the story and begin to provide meaning for those sentences. Withjoint inference, the knowledge integration engine 136 combines multiplelevels of interpretation, thereby interpreting the text at variouslevels of conceptual richness. As noted above, higher levels ofinterpretation are richer, but also more implicit and therefore harderto discover. The first level of interpretation is recognition of theexplicit natural language text found in the story. The second level ofinterpretation concerns the linguistic analysis performed by the storyparsing engine 134. The next two levels of interpretation—semanticanalysis to provide generative semantic primitives (i.e., level three)and frame semantics (i.e., level four)—are performed by the knowledgeintegration engine 136 (with the help of the knowledge induction engine140, the dialog engine 142, and framework 144) to discover meaningimplicit in the story.

In FIG. 9, the knowledge integration engine 136 has a joint inferenceengine 406 that can operate in a variety of ways. In one implementation,the joint inference engine 406 proposes multiple possible “worlds”,where each world has a set of beliefs that are considered true. Thebelief generation components 402 are iteratively run on worlds,observing the beliefs that are true and proposing distributions over newbeliefs. New worlds are created by drawing beliefs from thoseprobability distributions. The constraint components 404 are run toevaluate the probability of worlds. When the process is finished, themarginal probability of a belief is the sum of the probability of theworlds in which it is true. Since the marginal probabilities do notcapture the relationships between probabilities of beliefs, the systemmay also store the worlds themselves as part of the story model 132.Further, this may alternatively be accomplished for instance throughtechniques such as a Markov chain or Monte Carlo sampling.

In one non-limiting approach, the belief generation components 402include a linguistic analyzer 904, which produces probabilitydistributions over beliefs that express the linguistic structure of eachsentence or phrase within the linguistic analysis results 712, such aspredicate argument structure (PAS), word senses, entity types, andco-references. For example, the linguistic analyzer 904 may receive aworld containing the belief that the text, “The bat was flying towardhim” was true, and output a probability distribution containing thebelief that the bat was an animal with 80% probability and a baseballbat with 20% probability.

The belief generation components 402 may further include alinguistic-to-GSP mapper 906 that, based on information such as PAS andword senses, produces probability distributions over instantiated GSPsthat represent possible semantic interpretations of the text. Thelinguistic-to-GSP mapper 906 may use the frame inference processdiscussed above, making use of frames from the current world model 138that each contain a mixture of linguistic analysis result propositionsand GSP propositions. Continuing the previous example, thelinguistic-to-GSP mapper 906 might receive a world in which a bat was ananimal and was the subject of the verb “flying”, and produce aprobability distribution with 99% probability in a GSP where the bat wasthe agent of the flying action and a 1% probability that it was not(i.e., it was propelled towards him by some other means, like in thebaseball bat case). As represented in FIG. 9, the current world model138 maintains libraries of the GSP and frame semantic structuresinitially in their uninstantiated state, including a GSP library 908 ofuninstantiated GSP structures 910(1)-(G) and a frames library 912 ofgeneric frame structures 914(1)-(F).

The GSP structures 910(1)-(G) in the GSP library 908 may be predefinedto capture the meaning of various facts, situations, or circumstances.For instance, one GSP structure may express an action and the structureincludes roles that define the action such as a reifier, an agent, whathappens before the action, and what happens afterwards (i.e., elementsof Reifier, Agent, Before, After). Other GSP structures might express anexperience (with roles of Agent, Experience-relation (e.g., see, hear,etc.) and Stimulus), spatial location (with roles of Location-relation,Entity1, Entity2), temporal location (with roles of Temporal-relation,Event1, Event2), and possession (with roles of Owner, Possession).

The GSP structures 910(1)-(G) begin as uninstantiated concepts thatcorrespond to a basic kind of fact. For instance, there is a GSPstructure for spatial location that, when instantiated, provides meaningof a fact about spatial location. There is a GSP structure for temporalrelation that, when instantiated, means a fact about temporal relations.Each uninstantiated GSP structure 910 has its own specific set of rolesto be completed with information explicit or implicit in the story. TheGSP structure for spatial relation has one role for a first object orlocation, another role for a second object or location, and a third rolefor specifying a spatial relationship between the first and secondobjects (e.g., near, on, in, above, below, etc.).

A word or phrase from the story may correspond to more than one instanceof a GSP structure. For example, a single word can have a different GSPstructure instance for each word sense. The word “fall” may have oneinstance of a GSP structure for one sense (e.g., like that found in thesentence “A big raindrop fell on Chloe's face.”), a second GSP structureinstance for another sense (e.g., like that found in the sentence “Chloeslipped and fell in the mud.”), and a third GSP structure instance foryet another sense (e.g., like that found in the sentence, “Thetemperature fell ten degrees.”).

Compound GSP structures may also be defined where at least one role of astructure is filled with another GSP structure. As an example, supposethere is a GSP structure for communication (e.g., roles of agent,recipient, message) and a second GSP structure for a goal (e.g., rolesof agent, goal). The role of “message” in the communication GSPstructure may be filled by the goal GSP structure. This forms a compoundGSP structure that represents facts about communications where themessage being communicated is itself about a goal of some agent. Such acompound GSP may correspond, for instance, to the natural languagesentences, “Alice told Bob that Carol wanted a ticket.” or, “‘Pass thecorn,’ said Dan.” The nested relationships discussed above withreference to certain structures are examples of compound GSP structures.

FIG. 10 shows an example set 1000 of GSP structures 910 that can becomposed to express ranges of meaning for a corresponding text string(e.g., sentence). There are many ways to establish how structures shouldbe organized to express meaning In this example set 1000, basicstructures might include an action structure 1002 to express a change infacts in time, which includes elements or roles of before, time-of, andafter. There may be a location structure 1004 to express things found inplaces, which includes elements or roles of location, entity1, andentity2. As yet another example, there might be a belief structure 1006that expresses what facts an agent believes, with roles of agent,belief, and credence.

With reference again to FIG. 9, a frame 914 is a probabilitydistribution over propositions (such as GSPs) in a particular context. Asimple case is a set of propositions that are likely to be true in acontext, such as actions that typically occur in a particular place. Aframe refers to various participants, actions, attributes, and otherconceptual roles typically associated with the context. A frame 914 maybe thought of as the thing formed by grouping together relatedexperiences. In general, frames exist at different levels ofabstraction. A frame could represent a specific episode in whichentities refer to specific people, and equally a frame could represent avery abstract concept like friendliness in which little is known aboutthe entities. In frames, entities referred to in some of the roles ofthe GSP structures may not be specific entities like Ben and Ava in thestory, but rather more generic frame-specific roles like customer andwaiter. For example, a restaurant frame may contain two GSP structureinstances of action, including one action instance for the customer(with instantiated roles of Reifier:Sit; Agent:Customer; After:Locationat table) and another action instance for the waiter (with instantiatedroles of Reifier:Bring, Agent:waiter, After:Location of menu or food atcustomer).

Frames 914 can also refer to other frames. The restaurant frame, forexample, can refer to an eating frame that defines a collection of GSPstructure instances for an experience of consuming food and drink.Frames can also be arranged in a hierarchy so that a frame might inheritparticipants, actions and attributes from its parent frame. As oneexample, a fast food restaurant frame may be a child of a restaurantframe and inherit certain aspects of the restaurant frame. Frames mayalso be composed in a conflicting pattern. For example, in a restaurantframe, the guest pays for the meal. But, in a birthday frame, guests donot pay for their meal. Further to this latter example, frames can alsosay that propositions have low probability. For example, the morespecific birthday frame might suggest a low probability that you pay thebill, wherein that probability is much higher in a regular restaurantframe.

The current world model 138 may initially include a library of manuallycurated semantic frames, such as the library “VerbNet”. To prime thesystem, for instance, a set of verbs (e.g., the 100 verbs that childrenlearn first) codified in the VerbNet library may imported into thecurrent world model 138. Unfortunately, such hand curated resources donot scale. Thus, as the computing system learns, the current world model138 is no longer manually created, but instead learns from processingbackground corpora and through dialog with the human students andcollaborators.

In FIG. 9, the linguistic-to-GSP mapper 906 performs the frame inferenceprocess to identify a subset of uninstantiated GSP structures 910(1)-(G)stored in the current world model 138 that are likely to fit welltogether in the frames and to determine assignments of entities in thestory to variables in the GSP structures. The goal is to map languagefrom the linguistic structure to the GSP structure by defining variousentities that the language refers to and determining what GSP structureshold true of the entities. In the illustrated example, the linguisticstructure 714 has a verb predicate “bring” which may be determined tomost closely match the uninstantiated GSP structure 910 for action. Thematch may be determined through a keyword match (e.g., “bring” in thelinguistic structure 714 matches the word “bring” in this particularaction GSP structure 910) or through other search strategies such assimilarity, conceptual, and so forth. As shown, the action GSP structure910 includes roles for reifier name (reifier:bring), an agent(agent:person1), and an after-state (after:has) with a nestedproposition relating the fact that a possessor role (possessor:person2)has an associated possession role (possession:thing) In someimplementations, the module 914 may identify and select multipleuninstantiated GSP structures that may match the linguistic structure714. During the selection process, relevance or confidence scores may becalculated. GSP structures that score higher indicate structures thatmore closely match the linguistic structure 714.

After identifying one or more uninstantiated GSP structures 910, thelinguistic-to-GSP mapper 906 instantiates the GSP structure withinformation from the linguistic structure 714 to produce a GSP structureinstance 916. Here, the reifier role in the Ben and Ava story isidentified as “bring” (reifier:bring), the agent role is identified as“Ben” (agent:Ben), the possessor role is identified as “Ava”(possessor:Ava), and a possession role is identified as “food”(possession:food). The GSP structure instance 916 is an instantiatedversion with as much information from the story as possible.

In some cases, there may not be all of the information to fullyinstantiate the structure, which gives rise to uncertainty that formsthe basis for questioning human users as to their understanding of thestory to help discover missing elements. Furthermore, in some cases,more than one GSP structure instance is instantiated from different GSPstructures 910 to provide different possible meanings of the storyexcerpt. When multiple GSP structure instances are created from the samestory excerpt and those instances have similar confidence scores, thisalso prompts the system to query the human users as to which possiblemeaning might be more appropriate in the story and thereby gainknowledge of how the users understood the excerpt.

As another example, suppose a text reads, “The boy is at the park.” Thelinguistic-to-GSP mapper 906 may choose a GSP structure that handlesentities called “boy” and “park”, such as a location GSP structure withroles of object, relation, and location. The location GSP structure isinstantiated to capture the meaning of the text by filling in the roleswith the text information (e.g., object:boy; relation:at;location:park). If this sentence is modified slightly to “The boy wentto the park”, the linguistic-to-GSP mapper 906 may choose nestedarrangement with a first action GSP structure having an agent “boy” andan effect, where the effect references a nested location GSP structure.Consider the sentence, “The girl asked her mother for a bike.” Thissentence may best map to a cascading nest arrangement with aninstantiated compound GSP structure of a communication GSP structure(e.g., agent:girl; recipient:mom; message:goal structure), a goal GSPstructure (e.g., agent:girl; goal:possession structure), and apossession GSP structure (e.g., possessor:girl; possession:bike).

In FIG. 9, the belief generation components 402 may further include anepisodic frame inference module 918 that implements the frame inferenceprocess to retrieve one or more uninstantiated frames 914(1)-(F) fromthe current world model 138 that may be relevant to the current beliefsof the story. The frames are inferred in part based on the subset of GSPstructure instances 916 that are identified to represent a possiblesemantic interpretation of the text. The episodic frame inference module918 proposes probability distributions over episodic frames, alignsentities in the story to roles in the frame, and new beliefs areinferred from the frames. This process may occur iteratively to discoverthe frame hierarchy that explains the story. In the Ben and Ava story,for example, a restaurant frame 920, for example, may provide theimplicit information that Ben and Ava are in a restaurant, therebyproviding a theme or context within which to better understand theexplicit language in the story. The restaurant frame 920 may be selectedfor this purpose as having a higher likelihood of being relevant to astory that involves people, a menu, food, and tables, as compared topossible other frames for hotels or pubs.

The restaurant frame 920 is then instantiated by the episodic frameinference module 918 to include multiple GSP structure instances 916pertaining to the story. The restaurant frame, in its uninstantiatedstate, has general references to “customer”, “waiter”, and so forth. Theepisodic frame inference module 918 fills in the fields for this framewith the information from the story, such that the customer is alignedto Ava and the waiter is Ben.

In the Ben and Ava story example, there are seven sentences in the storyand the seven sentences may be represented by at least seven, and likelymore, corresponding GSP structure instances 916(1)-(7+). The firstsentence in the story (i.e., “Ava walked in.”) is represented by the GSPstructure instance 916(1) with the primary action term “walk” beingillustrated. The second sentence form the story (i.e., Ben showed Ava toa table.) is represented by the GSP structure instance 916(2) with theprimary action term “show” being illustrated. In each illustratedinstances 916(1), 916(2), . . . , 916(6), and 916(7), only the primaryaction (i.e., “walk”, “show”, “bring”, and “ate”) is shown, but this ismeant to convey the entire structure instantiated with other facts fromthe story.

In one implementation, the episodic frame inference module 918 maysearch and identify multiple frames that have varying degrees ofrelevance. Each search returns a confidence or relevance score that maybe used to select one or more frames. The frames to be ultimately chosenare expected to align with elements in the story in a way that bestexplains the story. For instance, the restaurant frame may be selectedbecause the story involves people, menus, food, and tables. However, themodule 918 may further identify a hotel frame, which too may be relevantto a story involving people, menus, food, and tables. Accordingly, theepisodic frame inference module 918 may select both a restaurant frameand a hotel frame, with perhaps the restaurant frame having a higherrelevance score than the hotel frame, but both having scores that exceedan acceptance threshold. In such situations, both frames are selectedand instantiated and then used to generate questions for the human usersto better understand which might be the best selection.

The belief generation components 402 may further include a common-sensereasoning module 922 that, given the GSPs already in the story model,produces new probability distributions over instantiated GSPs thatrepresent further semantic interpretations of the text. For example,such reasoning may include numerical reasoning like counting andarithmetic, temporal reasoning like event ordering, and physicalreasoning about parts and sizes of physical objects. The algorithms usedin the common-sense reasoning module 922 may be specialized toparticular GSPs (e.g., algorithms for counting the number of entities inthe story model of various types) or may be generic application of theframe inference process to retrieve and apply deductive rules. It isfurther noted that as stories become more complex, many frames may beused to represent the story. This is analogous to scenes or episodesthat come together to form the complete story.

The knowledge integration engine 136 further includes the constraintcomponents 404 that implement the evaluation phase of the frameinference process that examines how well the possible frames and GSPstherein represent the story. In one implementation, the constraintscomponents 404 produce a score for how well the set of frame alignmentsmatch the story. A higher score is given when a small number of framesmatch a large number of linguistic analysis beliefs extracted from thestory. Conversely, scores are lower when the inferred beliefs arecontradictory with the system's other beliefs about the story.

The joint inference engine 406 combines the output of all of thecomponents in the system to effectively combine the different levels ofinterpretation. The joint inference engine 406 takes the output from thebelief generation components 402 and the constraint components 404 andcalculates the joint distribution over beliefs. The joint inferenceengine 406 calculates the marginal probability of each belief, which isused to construct and evolve the story model. The joint inference engine406 may be configured to produce conditional probabilities for possiblebeliefs based on all beliefs as known at the time

By combining the results of all of the components mentioned above, thejoint inference engine 406 combines the different levels ofinterpretation. For example, consider the case where the story parsingengine 134 produces a probability distribution over predicate argumentstructure beliefs, where one of the predicate argument structure beliefshas low probability. If the linguistic-to-GSP mapper 906 determines thatGSP using the predicate argument structure belief fit well with anepisodic frame that also fit with the rest of the story, it would begiven a high marginal probability by the joint inference engine.

The GSP structure instances 916 and the frame instances 920 createdthrough this process may be stored in a store 924 in the current worldmodel 138 to continue building the knowledge of the computing system.These instances may further be used to build new GSP structures andframes for future use in building an understanding of a story.

FIG. 11 illustrates how the knowledge integration engine 136 uses frameinference to improve the understanding of the story. In this example,the Ben and Ava story 106 is shown along with an abstract restaurantscript or episode 1102, which may be represented by an uninstantiatedrestaurant frame structure 1104 to describe the episode within a unifiedtheme or concept. Here, the episode 1102 provides background knowledgeof what happens in a restaurant, as follows:

A restaurant is a place a customer goes to eat food.

-   -   At the restaurant, the customer sits at a table and waits for a        waiter to come.    -   The waiter gives the customer a menu.    -   The customer reads the menu.    -   The customer picks the food the customer wants to eat.    -   The customer tells their choices to the waiter, and the waiter        brings the food to the customer.    -   After the customer eats the food, the waiter brings the bill to        the customer.    -   The customer pays the bill and then the customer leaves.

The restaurant frame 1104 is composed of multiple generative semanticprimitives that are relevant to the sentences of the episode 1102. InFIG. 11, three uninstantiated action GSP structures 1106, 1108, and 1110are shown for discussion purposes. The action GSP structures 1106, 1108,and 1110 are embodied as data structures maintained in memory locationsof the current world model 138, as represented by memory location 1112.The first action GSP structure 1106 represents part of the openingsentence in the episode 1102, which says “A restaurant is a place acustomer goes to eat food.” The action GSP structure 1106 includes theaction role “go” (reifier:go) at a root node of the data structure, anagent role “customer” (agent:customer) at a first dependent node, and alocation role “restaurant” (location:restaurant) at a second dependentnode. The action GSP structure 1108 represents the second clause of thesixth sentence of the episode 1102, which reads, “ . . . and the waiterbrings the food to the customer.” The action GSP structure 1108 includesthe action role “bring” (reifier:bring) at a root node of the datastructure, an agent role “waiter” (agent:waiter) at a first dependentnode, a possession role “food” (possession:food) at a second dependentnode, and a possessor role “customer” (possessor:customer) at a thirddependent node. The third illustrated GSP structure 1110 represents thefirst clause of the seventh sentence of the episode 1102, which reads,“After the customer eats the food . . . ”. The action GSP structure 1110has an action role “eat” (reifier:eat) at a root node of the datastructure, an agent role “customer” (agent:customer) at a firstdependent node, and an object role “food” (location:food) at a seconddependent node. Notice that the various action GSP structures 1106,1108, and 1110 begin with generic labels in the various nodes of thedata structure (e.g., customer, waiter, food, etc.).

The knowledge integration engine 136 aligns the frame semantics in frame1104 with a story model interpretation 1114 to improve understanding ofthe story 106. In this example, the frame structure is instantiated withspecifics from the Ben and Ava story 106 to form instantiated GSPstructure instances 1116, 1118, and 1120 that correspond to theuninstantiated GSP structures 1106, 1108, and 1110, respectively. Ininstantiated GSP structure instance 1116, the argument of the agent roleis the story entity “Ava” in place of the generic placeholder“customer”. Since there is no more specific information in the storyabout a type or name of the restaurant, the location role maintains thegeneric label “restaurant”.

For the instantiated GSP structure instance 1118, the agent role of thegeneric placeholder “waiter” is replaced with the story-specific entity“Ben”. The possessor role assumes the story-specific entity “Ava” inplace of the generic label “customer”. The story entity “spaghetti” alsoreplaces the generic label “food” in the possession role. Similarly, forthe instantiated GSP structure instance 1120, the agent role of “waiter”is replaced with “Ava” and the object role of “food” is replaced with“spaghetti”. It is noted that the knowledge integration engine 136 mayconsider multiple possible alignments. The knowledge integration engine136 estimates the confidence scores with which each alignment fits withthe story. For example, the alignment with Ava as customer and Ben aswaiter is a better fit for the story then Ava as waiter and Ben ascustomer. More specifically, higher scores are given when a small numberof frames match a large number of beliefs extracted from the story.Furthermore, a set of frame alignments will score poorly if newlypredicated beliefs are contradictory with the system's other beliefsabout the story. Approaches to estimating confidence scores are contextdependent and task related, and hence may vary depending upon thesituation. The instantiated GSP structure instances 1116, 1118, and 1120are embodied as data structures maintained in memory locations of thecurrent world model 138, as represented by memory location 1122.

While the computing system's understanding of the story is now richerthan a basic syntactic parse, there may still be more to learn about thestory. The knowledge integration engine 136 may access induced knowledgeresources provided by the knowledge induction engine 140 to continue tolearn more about words and phrases used in the story. Additionally, theknowledge integration engine 136 may further invoke the dialog engine142 to engage human users to help resolve any discrepancies or gaps inthe instantiated data structures or ultimately choose among multiplepossible semantic structures that could plausibly explain the story. Theknowledge integration engine 136 may further work with the framework 144to build modified and newer versions of the GSP structures and framesthat are maintained in the current world library 138 based on what hasbeen learned by the story linguistic-to-semantic mapping exercise andany feedback from human users. For instance, the system can also explorelarge corpora of structured, semi-structured, or unstructured data (suchas text corpora, image or video collections, semantic data bases, etc.),using different layered mechanism to extract and compose new frames.These mechanisms include, but are not limited to, statisticalsupervised, semi-supervised, and unsupervised machine learning and datamining techniques for extracting statistically meaningful frames;logical and probabilistic reasoning, for generating new frames viadeductive or abductive processes from frames that are already stored;and interaction with users, through the dialog engine, to acquire directknowledge of new frames. The utility of an induced frame can beevaluated by its ability to predict the specific individual texts.

FIG. 12 shows an exemplary process 1200 that is executed by theknowledge integration engine 136 to infer semantic information for adeeper understanding of the story. The process 1200 is described withreference to the system architecture 100 and knowledge integrationengine 136 of FIGS. 1, 4, 5, and 9. At 1202, linguistic analysisresults, including a linguistic structure with syntax and PASannotations, are received. With reference to FIG. 4, the linguisticanalysis results may be received from the story parsing engine 134.

At 1204, frame inferences are made by converting the linguisticstructure to one or more semantic structures that provide higher levelsof interpretation. In one approach, the inferring operation involvesmultiple sub-operations represented by acts 1204(1)-(2).

At 1204(1), instances of generative semantic primitive structures areformed to provide a first higher level interpretation of what the textmight mean. As part of this formation, one or more pre-existing,uninstantiated GSP structures may be identified from a library of suchstructures, at 1204(1)(A). The uninstantiated GSP structures may bestored in the current world model 138 and identified based onprobabilities that the structures are relevant to the words/phrases inthe linguistic structure. Multiple uninstantiated GSP structures may beselected if they exhibit a sufficient probability that primitivesrepresent a likely meaning of the text. The probabilities may becompared to a predetermined threshold to aid the selection process. At1204(1)(B), the selected GSP structure(s) are instantiated with datafrom the linguistic analysis results. Once instantiated, these GSPstructure instance(s) provide a more robust range of meaning, providinglogical connections amongst facts and inferences.

At 1204(2), the frame inference operation further includes forming framestructures to provide a second higher level interpretation of what thetext might mean. One or more uninstantiated frame structures, whichexpress themes or episodic beliefs of the text, may be identified from alibrary of such structures, at 1204(2)(A). The uninstantiated framestructures may also be stored in the current world model 138 andselected based on probabilities that such structures exhibit a relevanceto the words/phrases in the linguistic structure. Multipleuninstantiated frame structures may be identified if they exhibit asufficient probability that the frames represent relevant themes withinwhich to understand the text (e.g., restaurant or hotel frames forunderstanding the Ben and Ava story).

In one approach, the frame selection act 1204(2)(A) may involve anadditional frame abduction processes to aid in determining which framesapply to a given text/story. This sub-process includes not only theframe alignment process described previously with respect to FIGS. 9 and11, but may additionally include a deduction process that derives moreand new inferences that arise from applying the frame in previoussituations. The applied frames in previous situations may be reviewedand analyzed for compatibility/consistency to evaluate how well thealignments and inferences fit together considering the prior backgroundknowledge.

At 1204(2)(B), the selected frame structure(s) are instantiated orconstructed with a collection of GSP structure instances. As illustratedin FIG. 9, for example, the restaurant frame structure is instantiatedwith the GSP structure instances 916(1)-(7) formed from the sevensentences of the Ben and Ava story 106. Once constructed, the framestructure(s) provide a more complete understanding of the text.

At 1206, the semantic structures (i.e., GSP structures and framestructures) are evaluated for their possible alignment with the currentrepresentation of the story model. The evaluation may involvecalculation of a score that indicates how closely the frames and GSPstructures align with the story.

At 1208, the joint distribution over the beliefs is calculated. In oneimplementation, the joint inference engine 406 calculates the marginalprobability of each belief, which is used to construct and evolve thestory model. The joint inference engine 406 may be configured to produceconditional probabilities for possible beliefs based on all beliefs asknown at the time.

At 1210, the most appropriate frames and GSPs are chosen to representthe story and the story model is updated. The current world model mayalso be updated with any information learned from the frame inferenceprocess.

Illustrative Knowledge Induction Engine

FIG. 13 shows an exemplary implementation of the knowledge inductionengine 140, illustrating select components that aid the knowledgeintegration engine 136 and dialog engine 142 when inferring semanticinformation about a text string or story. The knowledge induction engine140 may be implemented to run offline or independently of othercomponents in the learning and understanding modules 130 to generateresources that may be stored in the induced knowledge resourcesrepository 412 for easy access by the other components.

Narratives are tacit. Information is left unsaid, assumed, andambiguous. The computer system predicts tacit subjects, actions,relations; otherwise it will have trouble in understanding language. Theknowledge induction engine 140 has a set of components that help discernor predict knowledge that the author may leave implicit and unsaid inthe story from existing resources, and provide services to other systemcomponents such as the knowledge integration engine 136 and the dialogengine 142. The knowledge induction engine 140 attempts to fill in thesegaps so the knowledge integration engine 136 can form better knowledgemodels and the dialog engine 142 can articulate more intelligentquestions for the human students or collaborators. For example, when thestory says “the student got what he came to the university for,” theknowledge induction engine 140 finds alternative senses to predictwhether the sentence means the student earned a degree, or he receivedcredit for a course, or the student was educated. Each of thesealternatives may be accompanied by probability values of how likely eachalternative is within the broader context of the story.

At a high level, the knowledge induction engine includes a knowledgeaccumulation component 1302 and a knowledge induction service engine1304. The knowledge accumulation component 1302 accumulates data (bothlabeled and unlabeled) through various ways, including integratingexisting knowledge (e.g., unstructured data like text, images, audio,etc. and structure data like knowledge bases, existing logics, etc.),accumulating knowledge through dialogs, automatic knowledgebasecompletion using techniques like tensor decomposition and miningknowledge from data using the components in knowledge induction serviceengine 1304. The knowledge accumulation component 1302 processes thedata and produces a set of derived resources, i.e., induced knowledgeresources 412, which capture information implied by or latent in thedata.

The requests from the knowledge integration engine 136 and the dialogengine 142 are served by the induced knowledge resources 412 and theknowledge accumulation component 1302 if the requested knowledge isavailable. Otherwise, the knowledge induction service engine 1304 iscalled to generate the desired knowledge on the fly. The servicesinclude a number of modules that include, but are not limited to,modules 1306-1330 described below.

One component of the knowledge induction engine 140 is a word sensedisambiguator 1306 that may be executed to disambiguate word senses.Given a sentence, clause, or other text string, the word sensedisambiguator 1306 identifies the senses of nouns, verbs, adjectives,adverbs, and prepositions. In the case of nouns, for example, the wordsense disambiguator 1306 may differentiate between the word “ball” aseither a formal dance or a piece of sports equipment, or the word “bat”as either a flying mammal or another piece of sports equipment. Thedisambiguator 1306 may use sense-annotated resources compiled in variousways including, for example, training data, unambiguous word senses inlarge text corpora 410, and sample word-senses derived from runningalgorithms on the large text corpora 410. In other implementations, theword sense disambiguator 1306 may further access existing third-partysense inventories, such as WordNet for nouns, verbs, adjectives, andadverbs, or a publicly available preposition sense inventory.

In one implementation, the word sense disambiguator 1306 is embodied asprogrammatic software modules that include a vector calculator 1308 anda sense calculator 1310. The vector calculator 1308 generates differentvector representations for each syntactic token in a sense definitionand sums the vectors to produce a sense vector. The vector calculator1308 further computes a context vector for a word/phrase by treating thesentence without the word/phrase as the context, parse the reducedsentence, and produce a vector representation from the syntactic tokens.In one embodiment, an embedding algorithm is used to create the vectorsfor each syntactic token, such as word embedding that operates on tokens(rather than words).

The sense calculator 1310 is provided to estimate a prior for each sensefrom frequency information, such as that found in training data like thelarge language corpora 410. The sense calculator 1310 derives a sensefor the word/phrase as a function of the sense vector, the contextvector, and the prior. In one implementation, the sense calculator 1310may apply a cosine-similarity function for the sense vector and contextvector and weight each of the three inputs—sense vector, context vector,and prior.

The knowledge induction service engine 1304 may further include aparaphrase detector 1312 to find and recognize paraphrases in thesentence or text string. A paraphrase of a word or phrase is anotherword or phrase that is written differently but roughly has the samemeaning. For example, the phrase “crowd erupted” is approximately thesame as another phrase “applause in the stands”. The paraphrase detector1308 uses background knowledge from the large language corpora 410 andother sources to recognize similar phrases.

Yet another component of the knowledge induction service engine 1304 isa relation detector 1314 to detect relations among words or phrases. Therelation detector 1314 leverages the background knowledge from thetagged resources, like corpora 410, to predict words/phrases that mighthave relations. In one example, in the phrase “gas prices continue tofall”, the phrase “continue to fall” has a relation of decreasing anamount.

A text entailment detector 1316 may also be implemented as a knowledgeinduction service engine 1304 to decide if one piece of text entailsanother one. An entity detector 1318 may be included to classify a typeof word. A missing text generator 1320 identifies and creates text thatis implied in the story but not clearly mentioned. A text embedder 1322is another service that may be used to convert word/sentence/articleinto vectors. A rule mining tool 1324 is a service that learns inferencerules from text. In one implementation, the rule mining tool 1324 minesdifferent types of inference rules, such as rules involving only textualpropositions, rules involving only GSPs, rules mixing the two (i.e.language to knowledge mapping rules). An example implementation (basedon a frequent sub-graph mining approach) takes a set of frequentlyco-occurring statements from a large language corpus, generalizes theinstances to types (e.g., using word sense disambiguation), createspotential inference rule candidates using the generalized textpropositions, and validates by dialoging with a human user. A textmatcher 1326 is a service that may be used to match two pieces of text.

The knowledge induction service engine 1304 may further include a sceneanalyzer 1328 to predict what type of scenes may be inferred from texts.The scene analyzer 1328 explores known corpora 410 and other sources toidentify the most popular phrases under particular scenes. As oneexample, suppose a text reads, “I ordered some food and then drankcoffee.” The scene analyzer 1328 may explore background knowledgesources to detect scenes that contain the words/phrases such as “food”,“coffee”, “ordered”, “ordered some food” and “drank coffee.” In thisexample, the scene analyzer 1328 may return a ranked list of possiblescenes such as “coffee house”, “diner”, “commissary”, “crib”,“verandah”, “café” and “patio.”

The knowledge induction service engine 1304 further has a backgroundinformed, corpus-based inference module 1330 that trains on corpora 410and other sources (e.g., non-constrained sources like Wikipedia) topredict future semantic primitives from the background knowledge. As oneexample for discussion purposes, the inference module 1330 examinessubject-verb-object (or PAS) combinations in the corpora 410 andexplores what other combinations most closely resemble the targetcombination. Resemblance may be determined in various ways, such as by ascoring algorithm that computes relevance or likelihood of proximity ina text. For instance, suppose the subject-verb-structure contained “Daveeat food”. Other results may include, in ranked order, “Dave gainweight” (score of 4), “Dave lose weight” (score of 3), “Dave takecriticism” (score of 3), “Dave lose pound” (score of 2.5), “Dave drinkwine” (score of 2.5), and “Dave conquer tension” (score of 2.5). Asanother example, suppose the subject-verb-structure contained “I buycar”. Other results may include, in ranked order, “I give dollar” (scoreof 6), “repeat buy car” (score of 6), “I give deposit” (score of 6), “Ipay proof” (score of 5), and “I take car” (score of 4.5).

In the knowledge induction engine 140, the knowledge is stored inknowledge tensors 1332 as part of the knowledge accumulation component1302. A tensor is a multidimensional cube. The dimensions include (notlimited to) one or multiple entity dimensions, one or multiple relationdimensions, one or multiple frame dimensions, one or multiple temporaldimensions, one or multiple spatial dimensions and one or multiple scenedimensions. The knowledge accumulation component 1302 further includes aknowledge acquisition and population module 1334 that defines andpopulates the knowledge tensors 1332. In FIG. 13, a three dimensionalcube tensor 1336 is illustrated with two entity dimensions (e.g., commonnouns, semantic types, etc.) represented along two axes, and onerelation dimension (e.g., common verbs) along the third axis. A point inthe cube tensor 1336 contains the likelihood that the given relationholds between the two entities. In this example, suppose one entity is adog and the other entity is a squirrel. Now, suppose a tensorrepresenting a relation expressed by the verb “chase” is applied tothese two entities. The result of a dog chasing a squirrel is likely toresult in a high probability. Conversely, suppose the tensor representsa relation expressed by the verb “follow”, where the outcome is the dogfollows the squirrel. This is still a possible outcome, but may be ratedwith a lower probability than “chase” because while the dog is indeedfollowing the squirrel, the dog is really chasing the squirrel with theintent to catch the squirrel.

In one implementation, the knowledge induction engine 140 contains onetensor to contain all available knowledge and a set of applicationoriented tensors to cover each individual application.

In one approach, a tensor may be used to retrieve likely common senseknowledge from big data volumes of text. In the phrase “students earn .. . ”, the tensor query tool may identify several common candidates fromthe text like “credit”, “degree”, and so forth. In the phrase “playersearn . . . ”, the tensor query tool may identify other common candidatesfrom the text like “points”, “money”, and so forth. Once thesecandidates are found, similarities of terms and term pairs may becalculated, where each term is represented as a slice in the tensor andeach term pair is represented as a column in the tensor. Ranked lists ofcandidates with associated inference probabilities can be stored in theinduced knowledge resources repository 412 for query by the knowledgeintegration engine 136 to help align the story model 132 with thecurrent world model 138.

FIG. 14 shows a process 1400 that is executed by the knowledge inductionengine 140 to provide probable candidates for senses and relations ofwords/phrases in the story to aid the semantic inferences being made bythe knowledge integration engine 136. The process 1400 is described withreference to the system architecture 100 and knowledge induction engine140 of FIGS. 1, 4, 5, and 13. At 1402, queries for analyzingwords/phrases found in the story (or text string) are received. In thearchitecture 100, the knowledge integration engine 136 may submitqueries for words provided in the story that have been or will besemantically processed. The queries may include the words or phrases,tokenized versions of the words/phrases, or other representations ofwords/phrases.

At 1404, several analyses may be performed on the words/phrases receivedin the queries to deduce possible interpretations of the words/phrases.As these operations may be performed offline, the analyses for specificword phrases may have already been performed and results stored for easyaccess. In other situations, the analyses may be performed on the fly oras soon as practical. The various forms of analysis are represented byillustrative acts 1406, 1408, and 1410.

At 1406, word sense analysis is performed on the words/phrases todetermine possible senses. For each word/phrase, different vectorrepresentations are created using sense definitions and possible sensesare calculated as a function of those vector representations. Moreparticularly, one implementation of the word sense analysis 1406 isshown as acts 1406(1)-(4). At 1406(1), a sense vector is created foreach word/phrase. The sense vector is calculated by first parsing sensedefinitions corresponding to the word/phrase to produce syntactic tokensof each sense definition. These sense definitions may be maintained in arules or definitions datastore that may be part of the corpora 410 orinduced knowledge resources 412. Afterwards, the tokens for each sensedefinition are algorithmically processed to produce correspondingvectors, and these vectors are summed to produce a sense vector.

At 1406(2), a prior for each sense is estimated. Frequency informationfrom training data, such as the large language corpora 410, may be usedto estimate the priors. At 1406(3), a context vector is created for eachword/phrase. In one approach, a context is formed by removing theword/phase from the host sentence and then syntactically parsing thesentence sans the word/phrase. The syntactic parse is then converted tothe context vector using, for example, an embedding function. At1406(4), a sense for the word/phrase is derived as a function of thesense vector, the context vector, and the prior. In one implementation,a cosine-similarity function may be applied to the sense vector andcontext vector. Weighting may further be applied to these three inputs.The weighting may be learned using a supervised learning algorithm, suchas logistic regression.

At 1408, the words/phrases in the queries may be analyzed to detectparaphrases. relations, and/or entity types. Background knowledge fromtagged resources, like large corpora 410 or other sources may beexamined to identify one or more paraphrases, relations, and/or entitytypes that might apply to the words/phrases under analysis. At 1410, oneor more other services—text entailment detection, missing textgeneration, scene analysis, text embedding, text matcher, etc.—may beperformed.

At 1412, semantic primitives are predicted from background knowledgesources, such as large language corpora. As a background process, theinduction engine 140 may analyze corpora to examine varioussubject-verb-object (or PAS) combinations as to what other combinationsmight be relevant to them. Values of relevance may be computed based onhow related these combinations tend to be in large corpora. At 1414, tothe extent not otherwise produced through the analyses at 1404,probabilities are calculated to help rank the multiple interpretationcandidates discovered by the analysis. The probabilities may be passedback in response to the queries and used by the knowledge integrationengine 136 to select appropriate interpretations when inferring semanticand frame level understanding.

At 1418, knowledge is accumulated to produce a set of knowledgeresources. Some of these resources come with associated probabilities isa format or structure that can be easily consumed by other modules inthe system. In one approach, a three-dimensional tensor structure isused. With a tensor structure, three parameters (e.g., two entities andan action; one entity, one thing, one location; etc.) may be assessedusing different elements or values and probabilities may be computed foreach of those iterations. As noted in the example above, a tensor havingtwo entities and one action relation may be used to discover that astory involving a dog (first entity) and a squirrel (second entity) hasa higher probability of expressing a relationship among them as “the dogchases the squirrel” than perhaps “the dog follows the squirrel”.

At 1420, the resources are stored in an accessible datastore, such asinduced knowledge resources repository 412.

Illustrative Framework

FIG. 15 shows an exemplary implementation of the belief representationand reasoning framework 144, which is a set of foundational componentsused throughout the system such as a knowledge representation languageand inference and learning mechanisms for contextual differentiation andsemantic primitives. The framework 144 allows the system to store,index, retrieve, navigate, and manipulate probabilistic propositions (or“beliefs”) over time.

Generally, the framework 144 has a belief management system 1502, aknowledge database 1504, and knowledge representation (KR) languagedefinition module 1506. The belief management system 1502 is acollection of software-based functions for storing and queryingpropositions (or “beliefs”) that are represented according to the KRlanguage definition module 1506. The knowledge database 1504 is afeature store, graph database, knowledge base, etc. that treatsknowledge and reasoning as data and exposes these as simple and fastdata structures that are ontologically independent. In oneimplementation, the knowledge database 1504 is embodied as a fast JavaVirtual Machine-based in-memory concept database.

The KR language definition module 1506 maintains rules for a definedlanguage for representing entities and propositions, including a commonsyntax, minimal semantics, the degree of association among propositions,and common semantic modules for common types of propositions. The KRlanguage consists of two parts: a core representation language 1508 andcommon semantics modules 1510. The core representation language 1508defines a syntax and minimal semantics for how to represent entities andpropositions, and well as the degree of association betweenpropositions. The common semantics modules 1510 are types ofpropositions that are used for frequent tasks. In one implementation,the common semantic modules 1510 may comprise the following:

-   -   Logical Operators: and, or, not, implies, iff.    -   Descriptions and Roles: An entity may play the role of a        description (class) that subsumes other entities (instances).        For any predicate in the KR language, roles can be declared and        information provided about the expected class of the concept        that fills the role.    -   Names: Any concept can have a name    -   Collections: An entity may represent a collection of other        entities. This is related to descriptions, in that there is a        correspondence between any collection of things (the extension)        and a description that describes the members (the intension).    -   Uncertainty: Measure an associated probability of a proposition        being true.    -   Time: Indicator in which propositions are evaluated as being        true.    -   Beliefs: A representation of what proposition agents believe and        when.        Illustrative Dialog Engine

FIG. 16 shows an exemplary implementation of the dialog engine 142,illustrating select components that may be used to generate userquestions to challenge and/or confirm the system's current understandingof the story, and receive user responses for revising and extending theinterpretations implemented in the semantic structures and frames tomodify the system's understanding. The dialog system 142 allows thecomputer system 102 to engage in extended dialog sessions withindividual human users. Each dialog session may be carried out as aserial linear dialog involving only one user, or in a distributed mannerto distribute questions to multiple human users in parallel. Distributeddialog applies flexible dialog management in disassembling the contentof a dialog session to ask questions to different users and reassemblingthe results to achieve essentially the same or similar learned outcomeas a linear dialog. Distributed dialog sessions allow the computersystem 102 to scale by managing the cognitive load of questions across acrowd of users, thereby reducing latency of the learning process throughparallelized interactions with multiple users.

Dialog interaction in the collaborative learning process may serve oneof two purposes. The first is to support system learning and the secondto support user learning. In the first case, the system may notadequately map a story to GSPs with sufficient confidence, or fails tomake a necessary inference to fully understand the story. In thesecases, the system poses questions to users to solicit the missinginformation to accomplish the task. Through this learning process, thesystem may ask additional probing questions to generalize, specialize,or confirm what it has learned to ensure correctness in futureapplication of the knowledge. Examples of system learning strategiesinclude solicitation, confirmation, and generalization/specialization.Solicitation is a strategy in which the dialog engine asks a user tofill in gaps to complete system understanding. For example, the systemmay ask, “The story says ‘Ben showed Ava to a table’. Can you explainwhat “show” means in this context?”. In this case, a helpful user wouldrephrase the sentence in simpler terms to help the system understand,such as “It means ‘Ben took Ava to a table’.”

Confirmation is a strategy to confirm or validateinterpretations/inferences made about the story in which the system hasless confidence. For example, the system may ask “‘Ben took Ava to atable’ means ‘Ben and Ava walked and then they are both near the table’.Is that correct?” or in the Ben and Ava story, the system may confirminferred actions such as “I think that Ava paid the bill. Is thatcorrect?”. Generalization/specialization is a strategy that attempts toask additional probing questions to enhance the system's understandingafter the system has learned some new information. For example, thesystem may ask “Did Ava pay the bill because she is the customer?”(yes), “Do customers always eat spaghetti?” (no) “Do customers alwayseat food?” (yes in a restaurant) “Do customers always pay the bill?”(yes). This additional knowledge gained from generalization andspecialization helps the system apply the knowledge in appropriatecircumstances in the future.

In the case of supporting user learning, the system's role is to askquestions that will help the user better understand the story or reasonabout it. Note that some of the questions the system asks here may besimilar to what was discussed previously, with the primary differencethat now the system knows the answers to those questions. Some examplesstrategies for user learning include compare/differentiate,generalization/specialization, and inference. The system canautomatically switch between these two modes of operation depending onits reading ability relative to the user's ability.

In compare/differentiate, the dialog engine asks questions to help theuser differentiate among similar cases. For example, the system may ask“‘Ben showed Ava to a table’ means ‘Ben and Ava walked over to a table’.Can you tell me what ‘Ben showed Ava a table’ means?” Ingeneralization/specialization, the system asks questions to help theuser generalize/specialize their knowledge. For example, the system mayask “What else does a customer do in a restaurant that's not mentionedin the story?” or “Do all restaurants have waiters?” For an inferencestrategy, the system may ask questions to help users make inferencesthat are implicit in the story. For example, after reading that “Avapaid the bill and left Ben a good tip”, the system may ask “Do you thinkAva is happy with Ben's service as a waiter and why?”

With reference again to FIG. 16, the dialog engine 142 receives requests1602 from the knowledge integration engine 136 to resolve gaps betweenthe story model 132 and the current world model 138. The requests mayinclude information about the gaps to be resolved, low confidenceinterpretations to be confirmed, or other aspects that can help thesystem better understand the current story. When there is a questionabout a particular word sense, for example, the request may include theword, the sentence containing the word, multiple senses that the wordcan have, probabilities of those senses being the correct option in thesentence, a story identity, and so forth. Consider the sentence “Benbrought the food to Ava” in the Ben and Ava story 106. Suppose theknowledge integration engine 136 wants to learn more about which wordsense may be the most appropriate one for the word “brought” or its rootform “bring.” The request 1602 may include the complete sentence, theword “bring”, the various senses of “bring”, and so forth.

As requests are received from the knowledge integration engine 136, thedialog engine 142 begins one or more dialog sessions 1604 with humanusers, as represented by the student 110 and his/her device 118 and thecollaborator with his/her device 114. During the dialog session 1604,the dialog engine 142 generates and sends questions to the user devicesfor consideration and input by the human users and receives andprocesses responses entered into the user devices by the human users.

In the illustrated implementation of FIG. 16, the dialog engine 142 is aset of executable components that formulate questions, based on theattempted alignment of the story model 132 with the current world model138, and interact with one or more human users to obtain answers tothose questions. The user questions are formulated to fill or resolvegaps that arise where the system does not have sufficient confidence inthe current story model 132, is not yet able to confidently align thestory model 132 with the current world model 138, or attempts togeneralize/specialize the new information to facilitate futureapplication of the knowledge. The dialog engine 142 may further leveragereading comprehension questions and/or produce new questions for thestory as such questions can be useful for identifying gaps where thesystem's current story model plus current world model is insufficient tofully understand the story in its context.

The dialog engine 142 has a user question generator 1606 to formulatequestions to be posed to the human user during a dialog session 1604.The user question generator 1606 receives requests, such as the request1602, from the knowledge integration engine 136 and crafts questions todiscover information relevant to the requests. In one implementation,the user question generator 1606 has a natural language generationengine 1607 and a dependency structure builder 1608. The naturallanguage generation engine 1607 is used to render beliefs from the storymodel and current world model in natural language. The natural languagegeneration engine 1607 makes use of syntactic information, naturallanguage templates associated with GSPs, and background corporainformation from the knowledge integration engine 136 to generatenatural language that a non-expert user will be able to understand. Thedependency structure builder 1608 is provided to construct a dependencystructure 1610 from the data in the request 1602. A dependency structure1610 may be used to represent a dialog in a way that allows the systemto determine the parts of a dialog that are independent of one anotherand can be pursued in parallel. The dependency structure also allows thesystem to infer a dialog context for interpreting and answering aquestion, which is critical in a distributed dialog setting. In thisstructure, a root node represents a parent question and each child nodebranching from the root node represents a possible follow-up questionbased on the answer to the parent question. Using this representation,child nodes are dependent on their parent nodes while sibling nodes areindependent of one another.

In the illustrated example, a root node pertains to the question of wordsense (WS) of the word “bring” as received in the request 1602. Fromthis root node, three child nodes are shown for the three sensesreceived in the request, including “take” (i.e., sense option 1: “takesomething or somebody with oneself somewhere”), “cause” (i.e., senseoption 2: “cause to come into a particular state or condition”, and“legal” (i.e., sense option 3: “present or set forth legally”).Accordingly, a root question (RQ) of the dependency structure 1610 maysimply be to ask which sense of the word “bring” in the sentence, “Benbrought the food to Ava”, is most likely? Depending upon that answer,follow-up questions represented as questions Q1-Q6 may be askeddepending upon which word sense the human user selects initially. If theuser selected the “take” option, then the follow-up questions will be Q1and Q2, and may include questions about what the state was before theaction, and what the state is after the action.

FIG. 17 shows another example of a dependency structure 1700 (like thestructure 1610 in FIG. 16) in more detail, but this time using theexample sentence “A big raindrop fell on Chloe's face.” In this example,dependency structure 1700 is constructed to ask questions about thesentence itself, such as the sense of the word “fell” in the sentence. Aparent node 1702 contains the verb “fall”, as the root form of “fell” inthe sentence. Associated word senses form the possible branches from theparent node. A first branch 1704 corresponds to a first sense of theword “fall”, which means to “descend in free fall under the influence ofgravity”. The first branch 1704, which represents the correct word sensefor the sample sentence, leads to first child node 1706 that suggestsquestions pertaining to possible facts or relations implicit in thecorresponding word sense of free falling. Here, the first child node1706 suggests to ask questions about what happened before the raindropfell (i.e., Ask: Before State—“Where was the raindrop before it fell?”)as well as questions about what happened after the raindrop fell (i.e.,Ask: After State—“Where was the raindrop after it fell?”).

A second branch 1708 corresponds to a second sense of the word “fall”,which has a meaning to “suffer defeat”. This branch 1708 leads to asecond child node 1710 that suggests questions pertaining to possiblefacts or relations implicit in the corresponding word sense of sufferingdefeat. The second child node 1710 might suggest asking such questionslike “who suffered defeat?” (i.e., Ask: Who) and “how did they sufferdefeat?” (i.e., Ask: How). A third branch 1712 corresponds to a thirdsense of the word “fall”, which means to “be classified or included”. Athird child node 1714 terminates the third branch 1712 and suggestsasking follow-up questions pertaining to classification, such as “whatobject is being classified?” (i.e., Ask: Object) and “what is theclass?” (i.e., Ask: Class). A fourth branch 1716 corresponds to a fourthsense of the word “fall”, which means to “occur at a specified time orplace”. This fourth branch 1716 leads to a fourth child node 1718 thatsuggests questions pertaining to possible facts or relations implicit inthe corresponding word sense of occurring at a time or place. The fourthchild node 1718 might suggest asking such questions like “what eventtook place?” (i.e., Ask: Event), or “when did it take place” (i.e., Ask:Time), or “where did it take place” (i.e., Ask: Location).

In a different scenario, the system's question to the user may not bedirectly related to how a single sentence should be interpreted, butrather on how the information conveyed in the sentence should beintegrated into the system's understanding of the whole story. Forinstance, a parent node in this case may be “location of Chloe”, with acorresponding question “Is Chloe indoors or outdoors?” A follow-onquestion after the user chooses “indoors” may be “Why is it rainingindoors?” (turns out Chloe is in a rainforest in the story), while onewhen the user chooses “outdoors” may be “I think it is raining in thestory. Is that correct?” Dependency structures can be built similarlyfor scenarios where the system attempts to confirm, solicit, generalize,and specialize information it learned from the story.

Accordingly, the dependency structures 1700 may be constructed for eachof the various requests received from the knowledge integration engine136. The dependency structures 1700 provide the relationships among thevarious elements known to be part of the information being sought,thereby allowing the dialog engine to formulate appropriate questions toengage a human user.

With reference again to FIG. 16, the dependency structures 1610 built bythe dependency structure builder 1608 are provided to a question queuingengine 1612, which organizes the structures for the dialog sessions 1604with the users. The question queuing engine 1612 is shown with multipledependency structures 1610(1)-(Q) stored in a queue, with eachdependency structure having one or more questions therein, asrepresented by the questions Q1-Qn in structure 1610(1) and questionsQ1-Qm in structure 1610(Q). Each dependency structure represents thesystem's attempt to solicit information from the user to fulfill all orpart of requests such as 1602. The questions may be maintained in anordered list 1614 that can be made available for presentation to theusers.

The queuing engine 1612 provides the questions in its ordered list 1614to a question dispatcher 1616 for submission to the human users duringthe dialog session 1604. During the session 1614, the questiondispatcher 1616 sends the questions to the user devices 114/118. Thequestion dispatcher 1616 continuously dispatches questions from the list1614 to either a single user in a linear exchange or to multiple usersin a parallel manner. The question dispatcher 1616 includes a lineardispatcher 1618 that facilitates sessions with a single user. As oneexample, the linear dispatcher 1618 may engage with a singlecollaborator about the content of the Ben and Ava story. The lineardispatcher 1618 may formulate the first question about the sense of theword “bring” as derived from the root node of dependency structure 1610.The question may be dispatched and presented on a user device UI, asfollows:

-   -   Here is a sentence I'm trying to understand:        -   Ben brought the food to Ava.    -   What choice below uses the word “bring” most similarly to the        sentence above?        -   1. Take something or somebody with oneself somewhere.        -   2. Cause to come into a particular state or condition.        -   3. Present or set forth legally.            This is illustrated in FIG. 1, for example, as the dialog UI            126. After this initial question, suppose the user returns            the answer of option 1.

Responses received from users by the question dispatcher 1616 arereturned to the queuing engine 1612 for analysis of which follow upquestions to ask. When the user chooses an option (e.g., word sense“take” for the verb “bring”), the queuing engine 1612 traverses theappropriate dependency structure along the branch for that chosen optionto determine a new question. The new question is then added to thedialog list 1614 for the dispatcher 1616 to send out to the users.Continuing with the Ben and Ava story, appropriate follow-on questionsto be presented back to the same collaborator might be as follows:

-   -   Where is the food before it is brought to Ava?    -   Where is the food after it is brought to Ava?        Multiple choice answers may be provided for each of these        questions, if choices can be inferred, or an open dialog box may        be provided for the user to simply add an answer. One example        set of UIs is shown and described below in more detail with        reference to FIGS. 19-21.

The question dispatcher 1616 may alternatively distribute questions inparallel to multiple users through a distributed dispatcher 1620. Thedistributed dispatcher 1620 separates the questions and distributes themto multiple users in parallel. The distributed dispatcher 1620 may askthe same question to multiple people, or different questions todifferent people. Examples of distributed dialog sessions are providedbelow in more detail with reference to FIGS. 22-24.

Another example of follow-on questions using the sentence illustrated inFIG. 17 of “A big raindrop fell on Chloe's face” may include, forexample:

-   -   Dialog Engine: What is the sense of “fall” in “A big raindrop        fell on Chloe's face”? (Offers multiple choice options)    -   User: Option 1—Descend under the influence of gravity Dialog        Engine: What is the state of raindrop before “fall”?    -   User: It is in the sky.    -   Dialog Engine: What is the state of raindrop after “fall”?    -   User: It is on Chloe's face.        The two follow-on questions pertaining to the state of the        raindrop before and after the fall may be linearly dispatched to        the same person by the linear dialog dispatcher 1618 or        dispatched in parallel to two different people by the        distributed dialog dispatcher 1620.

The question dispatcher 1616 also sends responses from the users to ananswer aggregator 1622, which continuously aggregates informationobtained from question/response pairs returned from the dialog session1604. The question/response pairs may be stored as data structures 1624that associate the questions asked with the responses given. In theillustrated example, the data structures 1604 may associate eachquestion 1626 with a response 1628 to form a question/response pair,which is further associated with a story identity 1630. Additionalinformation may also be recorded, such as the user reference identity,date/time stamp, modality used, and so forth. When the dialog session1604 is completed, the aggregated information embodied in thequestion/response data structures 1624 corresponds to the resultslearned from interacting with humans. The question/response datastructures 1624 are returned to the knowledge integration engine 136 forintegration into the current world model 138 and further alignment withthe story model 132.

The dialog system 142 may further compose questions that work acrossmultiple sentences or multiple stories as the system learns more. Forinstance, in the Chloe example above, the dialog system 142 asked oneset of questions around the sense of the word “fall” as used in thesentence “A big raindrop fell on Chloe's face.” But suppose the storyabout Chloe has another sentence, “Chloe slipped and fell in the mud.”The knowledge integration engine 136 may want to examine the use of theword “fell” in this sentence, and contrast that against the use of theword “fell” in the first sentence. A dependency structure for thissecond Chloe sentence may be configured and the dialog engine may askquestions that engage the user in a continuing linear dialog session asfollows:

-   -   Dialog Engine: Is “fall” in “Chloe slipped and fell in the mud”        used in the same way as “A big raindrop fell on Chloe's face”?    -   User: No    -   Dialog Engine: What is the sense of “fall” in in “Chloe slipped        and fell in the mud”? (multiple choice questions provided)    -   User: Lose an upright position suddenly    -   Dialog Engine: What is the state of Chloe before “fall”?    -   User: She was upright    -   Dialog Engine: What is the state of Chloe after “fall”?    -   User: She is on the ground, in the mud

As the system learns and the knowledge integration engine discovers moreand more relations among words/phrases, semantics, and frames, therequests to the dialog engine may become more complex. The dialog engine142 may use these requests to craft increasingly more sophisticatedquestions. Beyond word senses and filling in facts and relationships,the dialog engine 142 may ask questions that begin to explore thecompleteness of frames in the story.

Accordingly, in one implementation, the dialog engine 142 may beembodied as a system-initiative dialog system with multiple operationalmodes, ranging from a basic learning mode to acquire word and framesemantic representations to an interactive mode to read a story togetherwith human students and ask questions when encountering difficultpassages of the story, as well as other modes of interaction withcomplexities in between. In the learning mode, the knowledge integrationengine 136 and the dialog engine 142 engage users to learn the basicmeanings of individual words within sentences and basic framerepresentations. This begins with learning the most commonly used words,such as the top verbs and nouns usually known by grammar students of 6-7years in age. These words are learned in the context of sample sentencesto ensure that proper word senses are learned together with how wordswith those senses typically behave grammatically. The learned semanticrepresentations for those target words then go through a generalizationprocess to produce general semantic representations for the target wordswhich then become the foundation for interpreting future sentences.

The learning mode may further be used to discover basic framerepresentations. To do this, the dialog engine 142 engages human usersin a discussion over what the user understands to be happening in thestory, even though such understanding is not explicitly set forth. Thedialog engine 142 may draft general questions about the story, such aswho is involved, where is the story taking place, how are the storyelements unfolding or behaving, when is the story unfolding, and soforth. For instance, in the Ben and Ava story, the dialog engine 142 maypose a question like, “After reading this story, can you say where Benand Ava were?” The user may answer in a “restaurant” or “pub”. Thedialog engine may use this response to frame yet another question like,“How did you know it was a restaurant (or pub)?” The user may furtherreply, “because Ben showed Ava to a table, gave her a menu, and broughther food.”

From this human interaction, the computing system 102 can learn if oneperson shows a second person to a table, gives the second person a menuand brings the second person food, that means the first person and thesecond person are likely to be in a restaurant. The knowledgeintegration engine 136 uses this learned information to revise andupdate frame representations. In some cases, the knowledge integrationengine 136 may leverage this user feedback to write abstract scripts orepisodes (e.g., episode 1102 in FIG. 11) by building frames that can beorganized and grouped into the episodes. In one approach, an abstractframe may be built for every noun, and then multiple frames may be usedwithin an episode.

As one more example of crafting more general questions designed to pullout higher level information for frame semantics, consider again theEnzo and Zoe story introduced in FIG. 1 as story 106(T). The story is asfollows:

-   -   Enzo and Zoe were running a race. Enzo fell. He hurt his knee.        Zoe looked back. She was almost at the finish line. She wanted        to win. If she kept running, she would win. Enzo was her friend.        Zoe stopped. She ran back to Enzo. She helped him up. “Thank        you,” said Enzo. “You're welcome,” said Zoe. “If I fell, I would        want you to help me. I'm glad I could help you.

From this story, the knowledge integration engine 136 may make requeststo know more about what a “race” is in general. In the request, theknowledge integration engine 136 may provide as much information as itknows, such as word senses for “race”, any semantic structures andframes that use the term “race”, and so forth. From that, the dialogengine 142 generates a set of one or more questions to extract knowledgefrom the user. For instance, one example set of questions might includethe following questions Q1, Q2, and Q3, below:

Q1: I see that this story is talking about a race. Which of these thingsare typically associated with a race?

-   -   a. a participant    -   b. a winner of the race    -   c. a finish line marking the end of the race        These choices may be provided in the request from the knowledge        integration engine 136 as being known from other uses of the        word “race” in other stories, frames, corporate, and the like.    -   Q2: Who in the story does these things?    -   a. participant    -   b. winner        These choices may be generated from type information and the        induction process of the knowledge induction engine 138.    -   Q3: Which of these actions typically happen in races?    -   a. participants run a race    -   b. participants want to win    -   c. participants fall    -   d. participants finish race by crossing finish line        These choices may be generated by substituting named entities in        the story with concepts/roles using information provided by user        when answering the second question Q2, or by mining statistical        associations from large background corpora.

Following this interaction, the system has new knowledge about a raceframe such as typical agents and actions associated with it. The raceframe may not be complete but it is still useful. The race frame may befurther constructed and filled out as the system encounters otherstories that happen to mention races.

FIG. 18 shows a process 1800 for generating questions to submit to humanusers to challenge the computing system's current understanding of thestory as currently reflected in the semantic structures and frames. Theprocess 1800 is described with reference to the system architecture 100and the dialog engine 142 of FIGS. 1, 4, 5, and 16. As above, theprocess 1800 is shown in two columns to generally depict operationsperformed by the system 102 separately from operations performed by theuser devices 114 and 118.

At 1802, a request is received from the knowledge integration engine 136to identify information that may trigger question formulation asdiscussed above. These factors may include missing information that canbe used to resolve gaps between the story model and the current worldmodel, as well as improve the system's confidence in its currentinterpretation. The request provides known information or currentassumptions about a word, or semantic structure, but seeks furtherinformation from the user to validate the system's currentinterpretation.

At 1804, one or more questions are generated to discover the missing orvalidating information relevant to the request. In one implementation,at 1806, question generation involves building a dependency structurethat allows the system to infer a dialog context for interpreting andanswering a question. The dependency structure may be embodied as atree-type data structure with root nodes and branches to children nodesthat allows the dialog engine to logically traverse the structure to askopening and follow-on questions. One such dependency structure is shownand described with reference to FIG. 17. At 1807, the natural languagegeneration engine 1607 uses syntactic information, natural languagetemplates associated with GSPs, and background corpora informationpassed in from the knowledge integration engine to render the beliefsfrom the story model and the current world model. In this way, thequestions are formed in a natural language that a non-expert user willbe able to understand.

At 1808, the questions supported by the dependency structures are queuedfor later distribution to the users. The questions may further beprioritized in a list so that questions are asked in an orderly fashionand as answers are received, certain dependency questions may be removedfrom the list as no longer necessary to ask. The questions can be rankedbased on various metrics such as utility of acquiring the answer to thequestion. The answers to the questions can also be ranked based onvarious metrics such as the system's confidence in the answer choice.

At 1810, one or more questions are posed to the user by sending thequestions from the computing system 102 over a network to the user'sdevice 114/118. At 1812, the questions are presented to the user, suchas in a dialog UI. At 1814, user input is collected and a response isreturned from the user device to the computing system 102.

At 1816, the response is processed to determine what questions might beasked next. Additionally, at 1818, the responses are aggregated andreturned to the knowledge integration engine for use in updating thecurrent world model.

In another implementation, the dialog approach may be used to determinewhich instantiated GSP structures and frame structures should be addedto the story model 132 or as updates to the current world model 138. Theknowledge integration engine 136 determines which GSP structures andframe structures are true interpretations of a natural language text ina story by searching the space of possible uninstantiated GSP structuresby combining a library of GSP structures according to a compositionalgrammar. These GSP structures are then instantiated with entities from astory as well as entities suggested from background corpora accessed viathe knowledge induction engine. The instantiated GSP structures arerendered in natural language using the natural language generationengine 1607. The natural language renderings of the instantiated GSPstructures are filtered using various resources, including for exampletextual entailment or n-gram resources, such as the text entailmentdetector 1316, from the knowledge induction engine 140.

The original text, along with filtered natural language renderings ofthe instantiated GSP structures, are presented to one or more users viathe dialog engine 142. The knowledge integration engine 136 analyzes theuser responses, performing reliability, probability, and thresholdanalysis, to determine which GSP instantiated structures should be addedto the story model 132 with what confidences. The resulting beliefs maythen be generalized and integrated into the current world model 138. Inthis way, the knowledge integration engine 136 implements an approach toautomatically create, score, and refine generalized rules for mappinglanguage/text to knowledge, via instantiating the GSP structures andframe structures. The knowledge integration engine 136 may furtherprovide a mechanism to encode language mapping rules that arelexico-syntactic-semantic in the GSP language and/or as frames. Userfeedback elicited during the dialog sessions may be used to evaluate andrevise the language mapping rules.

In addition to text interpretation and text-to-GSP rules, the system 102employs a method for extracting common-sense reasoning rules.Implications and associations are hypothesized between GSP structuresthat have been confirmed as true interpretations of a given text. Theimplications and associations are presented to the user in a generalform for confirmation. If these general propositions are confirmed,additional examples are searched and presented to the user for furtherconfirmation and refinement.

Illustrative Dialog User Interfaces

FIG. 19 shows a dialog user interface (UI) 1900 that facilitatesinteraction between the computing system and the user. The UI shown inFIG. 19, and others following, are examples provided for discussionpurposes. The actual interface can vary from the appearance in FIG. 19as various types of questions are generated. For instance, one or moregraphical features may appear different or may be omitted altogetherdepending on the questions, what information is being sought, thesize/type of the user's screen, and so forth.

In FIG. 19, the dialog UI 1900 is illustrated as a first screenrendering 1902 that can be displayed on the user's device, such ascollaborator's device 114(1), and seen by the user during a dialogsession 1604 between the computing system 102 and the human user. Thescreen rendering 1902 is illustrated as a web page rendered within abrowser. However, as noted above, this is merely one possibleimplementation and other technologies may be employed to facilitatepresentation and electronic user entry of questions.

The screen rendering 1902 includes a primary area 1904 that includes agraphical dialog interface 1906 along the left side. The graphicaldialog interface 1906 has a series of dialog boxes, such as boxes 1908and 1910. The dialog boxes are shown attributed to the source through agraphical indication, with the top box 1908 being attributed asoriginating with the computer system (as represented by a butterflyicon, although other symbols may be used), and the lower box 1910 beingattributed as originating with the user (as represented by the usericon). In this example, the system is trying to understand the word“brought” from the sentence “Ben brought the food to Ava” in the exampleBen and Ava story. A question to learn about the sense of the word“brought” is provided in the top dialog box 1908, as follows:

-   -   So, here is a sentence I'm trying to understand:    -   Ben brought the food to Ava.    -   What choice below uses the word “bring” most similarly to the        sentence above?

A response template offering multiple choices for possible answers isthen placed into a second dialog box 1910. In this example, the optionsinclude:

-   -   1. Take something or somebody with oneself somewhere.    -   2. Cause to come into a particular state or condition.    -   3. Present or set forth legally.        While attributed to the user (as visually represented by the        user icon), the dialog box 1910 is populated with multiple        choice content received from the computer system. The user        attribution conveys that the user is choosing one of the options        to provide a response back to the computer system on this topic        of word sense for the word “brought”. The response dialog box        1910 further includes general action items of “other” to request        other options, “not specified” to indicate that the story is not        clear on this point, and “skip” when the user is uncertain of        the answer to the question.

Also in the primary area 1904 are optional graphical boxes aligned alongthe right hand side. The graphical boxes may include a story descriptionbox 1912 to identify which story is being discussed and a storyunderstanding box 1914 to summarize the system's current understandingof the story being considered.

In this example, suppose the user selects option 1, which provides thesense of the word “bring” as used in “Ben brought the food to Ava” tomean “take something or somebody with oneself somewhere.” When thedialog engine receives this answer, it traverses the associateddependency structure to identify the next question. This next questionis then returned to the user device for presentation to the user, asillustrated in FIG. 20.

FIG. 20 shows a second screen rendering 2002 of the dialog UI 1900presented on the user's device following the screen rendering 1902 ofFIG. 19 to illustrate a next question in the dialog session. In thisexample, the dialog interface 1906 has been visually shifted upward sothat the edge of the last dialog box 1910 is partially visible at thetop of the primary area 1904. Beneath this dialog box 1910 is a newdialog box 2004 containing the next question that is articulated basedon the user response to the previous question. Since the user answeredwith option 1, the next question says:

-   -   Okay. Here is my next question.    -   I think “bring” tells me about an action: a change of some sort.        That is, something is different after the action happens.    -   Is that correct?

A response dialog box 2006 is also presented to the user with responsiveoptions of “yes” and “no”. Suppose the user agrees with the statement,and answers “yes” in the dialog box 2006. This response is returned tothe dialog engine, which again traverses the associated dependencystructure to identify the next question. This next question is thenreturned to the user device for presentation to the user, as illustratedin FIG. 21.

Also shown in the primary area 1904 in FIG. 20 is an updated version ofthe story understanding box 2008 to reflect information confirmed inpart by the user response. Here, syntactic roles are added to thesentence so that “Ben” is identified as the subject, “brought” as theverb” and “the food” as the object.

FIG. 21 shows a third screen rendering 2102 of the dialog user interface1900 presented on the user's device following the second screenrendering of FIG. 20 to illustrate yet another next question in thedialog session. Since the user confirmed in the last response thesystem's understanding of the word “bring” indicating an action, thenext question presented in dialog box 2104 investigates furtherknowledge that the user might understand about the story. In thisexample, the question may be:

-   -   Okay, here's the sentence we're reading:    -   Ben brought the food to Ava.    -   At this point, I understand that:    -   Ben makes the bring action happen.    -   Here is my next question:    -   What sort of thing changed because of the bring action?

A response dialog box 2106 is also presented to the user with multiplechoices for possible answers. In this example, five options arepresented:

-   -   1. The food is located somewhere.    -   2. Ben is located somewhere.    -   3. Ava has the food.    -   4. The food is located in some relation to Ava.    -   5. Ben is located in some relation to Ava.        The user may select one or more of these options, or one of the        general action items in the box 2106 of “other” to request other        options, “not specified” to indicate that the story is not clear        on this point, and “submit” to send the answer back to the        system.

An updated version of the story understanding box 2108 is provided inprimary area 1904 to reflect information confirmed in part by theprevious user response. The confirmed meaning of “bring means takesomething or somebody with oneself somewhere” is provided to show anenhanced understanding of the sentence in the story.

The dialog engine continues to ask more questions until all of therelevant questions represented in the dependency structure have beenexhausted. The dialog engine may further ask open ended readingcomprehension questions. This body of knowledge, such as thatrepresented in the story understanding box 2108, is aggregated by theanswer aggregator 1622 and returned to the knowledge integration engine136 for further processing.

Illustrative Distributed Dialog System

As previously introduced, the dialog engine 142 may establish dialogsessions with a single user in a linear fashion to discuss the naturallanguage text of a story. These dialog sessions often extend beyondone-shot exchanges in that multiple pieces of information are sought andlater exchanges may depend on answers to earlier questions. For example,when the computing system is working on the sentence, “Frogs breathethrough their skin”, the dialog engine 142 may be tasked by theknowledge integration engine 136 to engage in a dialog session with auser to learn that breathing is a circular process of inhaling andexhaling air; the purpose of which is to obtain oxygen that the frogbody needs, and most animals breathe through their noses instead ofthrough their skin. In some cases, such extended interactions with asingle user may place a high cognitive load on the user and the serialnature of the dialog session takes time to execute.

To accelerate the learning process, the dialog sessions may be expandedto engage multiple users in parallel. The dialog sessions are segmentedinto sub-dialogs in which certain individual questions within adiscussion about the story may be answered by users independently ofothers. In the frog dialog session, for example, the mechanism andpurpose of breathing may be explored independently of the organsinvolved. Distributing question-and-answer sessions over multiple users,and engaging the users in parallel, allows the computing system to learnmore quickly.

Accordingly, in certain implementations, the dialog engine 142 employs adistributed dialog dispatcher 1620 to break up the dialog sessions intosub-dialog sessions and distribute those sub-dialog sessions to a wideraudience of users in parallel. In one implementation, the distributeddialog dispatcher 1620 leverages the dependency structure associatedwith the sentence or text string to break up the dialog sessions,allowing the system to flexibly manage the cognitive load placed on theuser by distributing its questions to multiple users. In this way, thesystem is logically having a single dialog session whose load isdistributed to multiple users in practice.

FIGS. 22-24 illustrate one example implementation of the distributeddialog system in more detail. FIG. 22 shows the dialog engine 142 inwhich the distributed dialog dispatcher 1620 distributes questions2202(1), 2202(2), . . . , 2202(P) over a network 120 to multiple users,such as collaborators 114(1)-(C). The same questions may be posed tomultiple people, or different questions may be distributed to differentsets of users. The collaborators 114(1)-(C) may be viewed as a crowd ofusers who are informally gathered or formally organized through aservice like Amazon Mechanical Turk™. The users review the questions andreturn their responses 2204(1), 2204(2), . . . , 2204(P) to the dialogengine 142.

The distributed dialog dispatcher 1620 includes a structure crawler 2206to iterate through the dependency structures, such as dependencystructure 1610 or their ordered representation in the dialog list 1614,based on the user responses to identify the next question. The structurecrawler 2206 uses the user response from the previous question to choosethe appropriate branches and discover what else needs to be learned. Insome cases, the dependency structure 1610 leads to multiple possiblefollow-up questions, often represented as sibling nodes in the datastructure. When this occurs, the different options for next questionsmay be presented in parallel to different collaborators.

A user selector 2208 may then select one or more groups of people tosend the follow up questions. The user selector 2208 may elect to sendthe same question to multiple people, such as the group represented bycollaborators 114(1)-(2). Alternatively, the user selector 2208 maydecide to send different question to different users or sets of users.For instances, as illustrated in FIG. 22, the user selector 2208 maychoose to send different questions 2202(1)-(P) to different users, suchas collaborators 114(1)-(C). In this manner, questions can be assessedand answered in parallel by many users. This permits the computingsystem to scale and learn more quickly. The computing system may bereading any number of books in parallel and engaging any number ofpeople in parallel, thereby allowing the system to gain understandingmore rapidly.

The user selector 2208 may use heuristics and profile information todetermine who should receive the questions. In one implementation, thecollaborators may have profiles that provide information about them,such as age, reading level, example books they have read, etc.Similarly, the stories or text may have associated profile information,such as reading or grade level, vocabulary rating, and so forth. Theuser selector 2208 may compare the profiles for users with the storiesand attempt to map appropriate levels between the two. For instance, ifthe text is suitable for a high school reading level, the user selector2208 may identify users with a high school reading level or higher.

FIG. 23 illustrates one example distributed dialog session involvingmultiple users. In this example, the dialog engine 142 is working withthe sentence, “A big raindrop fell on Chloe's face”. The targetinformation for the dialog session is to discover or confirm the propersemantic interpretation of this sentence, beginning with the word senseof the verb “fall”. The distributed dialog dispatcher 1620 may ask afirst set of users 2302 an opening question, as represented in dialogbox 2304, of “What is the sense of “fall” in “A big raindrop fell onChloe's face?”. Suppose that the response from a majority or all of theusers in the first set is option 1, “descend under the influence ofgravity”, as represented by dialog box 2306.

Based on this response, structure crawler 2206 discovers from thedependency structure that there are two possible follow-on questionspertaining to the before and after states of the raindrop. Further, thetwo follow-on questions are represented by sibling nodes in thedependency structure, so the questions may be asked in parallel todifferent users. Accordingly, the user selector 2208 chooses to send thefirst follow-on question, represented by a dialog box 2308 to the samefirst set of users 2302. The first follow-on question asks, “What is thestate of the raindrop before ‘A big raindrop fell on Chloe's face’”? Inparallel, the user selector 2208 sends the second follow-on question,represented by a dialog box 2310, to a different set of users 2312. Thesecond follow-on question asks, “What is the state of the raindrop after‘A big raindrop fell on Chloe's face’”?

Each set of users may then answer these questions concurrently. For thefirst follow-on question 2308, suppose most or all of the users in thefirst group 2302 chose option 3, “It is in the sky” as the before stateof the raindrop, as represented by dialog box 2314. Similarly, for thesecond follow-on question 2310, suppose most or all of the users in thesecond group 2312 choose option 2, “It is on Chloe's face”, as the afterstate of the raindrop, as represented by dialog box 2316. As shown inthis example, the questions are distributed to two groups and yet thesystem achieves the same result as if it had asked the two questionssequentially to the same person. But, the same result was achieved inless time and put less load on each individual user.

FIG. 24 illustrates another example distributed dialog session involvingmultiple users. In this example, the dialog engine 142 is working withthe text, “Enzo and Zoe were running a race. Enzo fell”. The targetinformation for the dialog session is to discover or confirm the correctsemantic interpretation of the two sentences, starting with the wordsense of the word “fall”. The distributed dialog dispatcher 1620 may askan opening question to a first set of users 2302, such as “Is ‘fall’ in‘Enzo fell’ used in the same way as Chloe slipped and fell in the mud?”,as represented in dialog box 2402. Concurrently, the distributed dialogdispatcher 1620 may ask a different opening question to a second set ofusers 2312, such as “What is the sense of ‘fall’ in ‘Enzo fell’?”, asrepresented in dialog box 2404.

In FIG. 24, suppose the second set of users 2312 generally respond tothe second opening question 2404 with an answer “lose an uprightposition suddenly” as represented by the dialog box 2406. Based on thisresponse (R1), two other follow-on questions are generated, asrepresented by dialog boxes 2408 and 2410. The distributed dialogdispatcher 1620 distributes a first follow-on question 2408 to the firstgroup of users 2302, asking “Chloe was upright before ‘Chloe slipped andfell in the mud’. Was Enzo upright before ‘Enzo fell’ too?”, asrepresented by dialog box 2408. In parallel, the distributed dialogdispatcher 1620 distributes the second follow-on question 2410 to thesecond group of users 2312, asking “Chloe is on the ground and muddyafter ‘Chloe slipped and fell in the mud’. Is Enzo on the ground, in themud, after ‘Enzo fell’?”, as represented by dialog box 2410. Notice thatthese questions may be asked independently from each other and hence,the different user groups may provide responses to the questions withouthaving to know about the other questions and groups who are answeringthem. In the described implementation, these follow-on questions arefound at sibling nodes in the dependency structure, and the distributeddialog dispatcher is free to distribute them to different users.

Suppose the response to the second follow-on question 2410 is generallythat Enzo is on the ground but not in the mud, as represented by thedialog box 2412. Based on this response (R2), two more follow-onquestions may be generated and distributed in parallel to groups ofusers. To the first group of users 2302, the distributed dialogdispatcher 1620 distributes a follow-on question asking, “Is it truethat all people are on the ground after they fall?”, as represented by adialog box 2414. To the second group of users 2312, the distributeddialog dispatcher 1620 distributes another follow-on question asking,“When is someone in the mud after they fall?”, as represented by adialog box 2416.

The users may respond to these follow-on questions and the dialogsession may continue until the dialog engine 142, under direction fromthe knowledge integration engine 136, has asked all of the questionsabout a story. The responses are aggregated and returned to theknowledge integration engine 136 for use in revising the current worldmodel 138, and aligning the story model 132 to the revised current worldmodel. After the questions are exhausted and the story is more deeplyunderstood, the story model is deemed completed, as will be described inthe next section with reference to FIG. 26.

FIG. 25 shows a process 2500 for distributing questions during dialogsessions to multiple users. The process 2500 is described with referenceto the system architecture 100 and the dialog engine 142 of FIGS. 1, 4,5, and 16, and 22. The process 2500 may be executed by the computingsystem 102, and specifically by the dialog engine 142.

At 2502, a target text string and an associated dependency structure arereceived. The text string may be a sentence, for instance, or otherphrase or clause. The dependency structure is a tree-type data structurein which children nodes represents possible follow-on questionsdepending upon answers to the parent node. One dependency structure isshown for discussion purposes in FIG. 17.

At 2504, a root or parent node is first found within the dependencystructure to identify an opening question in a sequence or series ofquestions to be asked during a dialog session. For instance, withreference to FIG. 23, the dialog engine may initiate a dialog session todiscover the word sense of “fall” and one parent node in thecorresponding dependency structure may represent an opening question of“What is the sense of ‘fall’ in ‘A big raindrop fell on Chloe's face’?”.At 2506, the dialog engine determines whether to send that question toone or more users. If one user (i.e., the “no” branch from 2506), thequestion dispatcher sends the question to a single user, at 2508. On theother hand, if multiple users (i.e., the “yes” branch from 2506), thequestion dispatcher sends the same question to multiple users, at 2510.Multiple users may be selected in situations where the system desires tosurvey the users, such as when the questions are offering multiplechoice answers with many possible answers. A majority of one choice mayserve as the appropriate answer.

At 2512, one or more responses are received from the user(s) andanalyzed. Based on these answers, at 2514, the structure crawler of thedialog engine traverses the dependency structure to find one or morefollow-on questions. In some cases, this involves moving down thetree-type structure from the parent node to one or more child nodes. Ifmultiple children nodes are at the same branch, the associated follow-onquestions may be considered independent of one another. Accordingly, at2516, it is determined whether the follow-on questions represented inthe dependency structure are associated with sibling nodes. If they are(i.e., the “no” branch from 2516), the question may be sent to one ormore users, at 2518. Conversely, if there are multiple sibling nodes(i.e., the “yes” branch from 2516), the different follow-on questionsmay be distributed to different sets of one or more users per set, at2520.

At 2522, one or more responses are received from the users and furtheranalyzed. If more questions can be asked about the same sentence or textstring, the process 2500 continues with further traversing of thedependency structure, at 2514. If all questions within the dependencystructure have been pursued, the process 2500 may continue with a newtext string at 2502.

Illustrative Story Model

After all of the user questions are asked and the responses areprocessed, the knowledge integration engine 136 does the final alignmentof the story model with the current world model. The knowledgeintegration engine 136 has gained a sufficient degree of confidence andis ready to output the story model 132 for storage and indexing. Thestory model 132 evolves throughout the process to its final state, aswill now be illustrated with reference to FIG. 26.

FIG. 26 shows an exemplary illustration of the story model 132 and howthe story model evolves over time as a result of the processes describedherein. For each story, the story model 132 is initially populated withthe linguistic analysis results 712 containing the linguistic structures714, entity types 726 and co-reference chains 730 derived from thesyntactic parse of the story. This is illustrated for explanationpurposes in FIG. 26 as “version 1”. Through the semantic processing,inferring, and human dialog sessions, additional information about thestory is learned. Semantic structures and frames representing the storyare iteratively revised to fill in more nodes and to add morerelationships. This is represented in FIG. 26 by the versions 2 throughFV-1 (i.e., next to last final version). Early, in version 2 forexample, the system might discover that an action for “walk” includesinformation pertaining from where the person walked and to where he/sheis going. Accordingly, a semantic structure is created and informationis sought to fill in the nodes. Over time, the system may further learnthat the person, Ava, was walking to a restaurant, and that restaurantwas an Italian restaurant.

After most or all of the semantic structures and frames are filled in,and confidences about the semantic structures and frames rise to asufficient threshold, and the user has confirmed much or all of theassumptions, a final version may be generated as represented by theversion FV (final version) in FIG. 26. The final version FV includesfinished semantic structures and frames that are completely filled in.Words have their correct sense, and relationships between them are trueand correct. Further, information not implicit in the story has beeninferred and added. At this point, the story model is deemed to besatisfactorily aligned with the current world model. For furtherconfidence, the system may further pose reading comprehension questionsto the users so that they can confirm whether the system's understandingis correct. The final version of the story is stored and indexed. All ofits knowledge is also contained in the current world model whichcontinues to evolve as more stories are consumed.

Growth of Computing System's Understanding

FIG. 27 shows a process 2700 for growing computer understanding overtime through the iterative processing of increasingly more difficultnatural language stories and the engagement of humans to evaluate,improve, and validate the system's understanding. The process 2700 isperformed by the learning and understanding computing system 102.Generally, semantic structures, such as GSPs and frame structures, areinferred using the inference processes described above to generaterepresentations of the stories. The inference process uses informationmaintained in the current world model 138, as well as other resourcesthroughout the system (GSP database 408, induced knowledge resources412, etc.). Dialog sessions are conducted with one or more human usersto evaluate the semantic structures as understandings of the stories.Any knowledge learned through the inference process and human dialog isstored in the current world model as revised and expanded semanticstructures. As more stories are ingested and processed, the currentworld model expands over time, thereby increasing the system'sunderstanding. With the expanded knowledge, the computing system becomescapable of handling more difficult subject matter with higher readingcomprehension levels.

According to one implementation, at 2702, multiple stories of an initialreading comprehension level are received by the computing system 102over a first period of time. For instance, the computing system 102 mayingest easy texts to start, such as early stage reading levels ofpre-school, kindergarten, or early grades. The stories may beaccompanied by a number of reading-comprehension questions. At 2704, foreach story, a story model is developed to represent the story. Thedevelopment of the story model includes the processes describedpreviously. For instance, at 2706, the story is parsed to syntacticallyanalyze the story and produce linguistic analysis results (e.g.,syntactic parse, predicate-argument structure, entity type assignment,co-reference) for each sentence. This may be performed, for example, bythe story parsing engine 134.

At 2708, one or more semantic structures are inferred as arepresentation of each parsed sentence by semantically processing thesyntactic representation of the parsed sentence. In one implementation,the knowledge integration engine 136, knowledge induction engine 140,and belief representation and reasoning framework 144 perform varioustasks in support of this act 2708 to create an initial semanticrepresentation, in terms of a small number of semantic primitives, usingthe linguistic analysis results. These modules draw upon the systemresources, such as the current world model 138 of what is true about theworld, the GSP database 408, and the induced knowledge resources 412induced automatically from large language corpora 410, as describedabove in more detail. At 2710, the evolving story model is evaluatedagainst the current world model to determine, in part, where the storymodel does not contain a high-confidence semantic representation thatfits well with the known frames in the current world model 138.

At 2712, a dialog session is established with one or more human userswho have also read the story to probe the user's understanding of thestory, and/or to improve, test, or challenge the system's understandingof the story. The questions are submitted to the user devices 114/118and presented to the user for review and consideration. At 2714,responses are received from the user devices and used to revise semanticstructures. The users' answers may be applied to update the system'sunderstanding of the story expressed in the current world model 138 ofwhat is true about the world. The dialog engine 142 may be used tofacilitate the dialog session and the knowledge integration engine 136may be used to revise the semantic structures according to the userfeedback.

At 2716, the current world model 138 is updated with any new knowledgelearned from the dialog session and any revisions to the semanticstructures. This knowledge may be used to further create new,uninstantiated GSP structures that are stored in the GSP database 408.As the computing system 102 reads and processes more stories, more GSPstructures (both uninstantiated and instantiated) are created over timeand the resources in the GSP database 408 and the knowledge in thecurrent world model 138 increase over time. The current world model 138can be made up of a collection of frames, which are probabilitydistributions over propositions (including but not limited to GSPs). Asthe computing system 102 reads and understands more text, it creates newframes that are used to interpret the stories.

At 2718, the story model for the current story is stored in the storymodel data store 132 and maintained by the computing system 102. Thestory models may be used in the future for inferring or understandingother stories, some with higher reading comprehension levels.

At 2720, the computing system 102 continues to receive and processadditional stories of increasing complexity, such as stepping up to thenext reading comprehension level. With each ingested new story, thecomputing system 102 again develops a story model (at 2704) whichinvolves inferring meaning from the story and testing its understandingwith humans. As the story model is developed, the system 102 updates thecurrent world model 138 with new knowledge (at 2716) and stores thestory model for future use (at 2718). This process is repeated over andover so that over time the learning and understanding computing system102 builds up a large and increasingly sophisticated knowledge baseexpressed as knowledge data structures of entities and propositions,such as through an associated set of instantiated generative semanticprimitives and frame structures.

FIG. 28 is a diagrammatic illustration 2800 showing how knowledge,embodied as semantic structures in a current world model 138, grows overtime as more stories of increasing reading comprehension levels aresubjected to syntactic processing, semantic processing, and humanevaluation through dialog. At an early or initial instance along atimeline 2802, the learning and understanding computing system 102 readsrelatively easy stories S1-Si (reference generally as 106) with aninitial or entry level reading comprehension. These stories may beappropriate, for example, for kindergarten students or early gradeschool students. The current world model 138 may be pre-populated withsome semantic structures or built from scratch. At time T1, the currentworld model 138(T1) is shown having a relatively smaller set ofinstantiated GSP structures 2804(T1) and frame structures 2806(T1).

Over time, the system 102 reads and processes more stories Sj-Sm, whichare more complex than the entry level stories S1-Si. For instance, thestories Sj-Sm may be considered moderate reading comprehension level,such as upper grade school or perhaps middle school and junior high. Attime T2, the current world model 138(T2) expands with more knowledge, asshown by substantially more sets of instantiated GSP structures 2804(T2)and frame structures 2806(T2).

Similarly, continuing over time, the system 102 reads and processes evenmore stories Sn-Sz, which are more complex than the previous storiesS1-Sm. These stories Sn-Sz may represent texts of higher readingcomprehension levels, such as those found in high school or at theuniversity level. At time T3, the current world model 138(T3) isexpanded to house significantly more sets of instantiated GSP structures2804(T3) and frame structures 2806(T3).

Accordingly, the computing system's understanding of language is a timedependent, probabilistic network of beliefs as expressed through thesesemantic structures. The network expands over time as the computingsystem reads and understands more stories. The system's understandingmay be represented through many different forms of visualization, whichallow end users and developers to explore the system's understanding andlearn more about how the system works and is working.

FIG. 29 shows one example set of visualizations 2900 that illustratesthe dynamic process of incrementally formulating a network ofprobabilistic beliefs and iteratively refining its global logicalconsistency. In one implementation, the learning and understandingcomputing system 102 includes a visualization module 2902 that generatesvisualizations of the system's understanding. These visualizationsinclude a first or story level visualization 2904 that illustrates anetwork of beliefs about a single story and a story galaxy visualization2906 that illustrates relationships amongst many constellations ofstories. The visualization module 2902 enables user controls, such as azoom control that allows the user to zoom in to a single story view 2904(or even nodes therein) or zoom out from the single story view 2904 tothe galaxy visualization 2906, as well as any range of views in between.

In the illustrated example, the single story visualization 2904 consistsof layers or rings of nodes 2910 and arcs 2912. Each node 2910represents a logical hypothesis about what belief is true. Each arc 2912extends between a pair of nodes and conveys a relationship indicatingthat one belief supports the truth of another with some probability. Thenodes are arranged in layers or rings 2914 to represent differentclasses of beliefs. For example, beliefs about the existence of specificsentences in a narrative might be one ring. Beliefs about the possiblemeanings of words or phrases might be the next ring. An inner ring2914(1) and an outer ring 2914(2) are called out in FIG. 29 to show theexistence of such rings. The nodes 2910, arcs 2912, and rings 2914 maybe further color coded to differentiate them throughout thevisualizations.

In another implementation, each layer or ring has one or more subringsor substructures to allow for the illustration of an arbitrary number ofbeliefs (nodes) and supports (arcs) in that layer or ring. In oneimplementation, the nodes and their attached arcs in a layer or ringanimate to illustrate that as new data is considered by the underlyingdriver or algorithm in one of the modules 130, new hypothetical beliefsare added to the network ring. For example, rings may spin, split,collapse and/or vary their node density to allow for more hypotheses.

A change in the appearance of a node 2910 or arc 2912 may represent, forexample, the confidence with which it is believed. For example, theopacity of a node or edge might be a function of the system's confidencethat the corresponding belief is true. Beliefs considered absolutelytrue would be completely opaque whereas beliefs considered absolutelyfalse would be completely invisible. Beliefs considered somewherebetween those two extremes would have a corresponding transparency.

A change of appearance may further illustrate the system's inferenceprocess. For example, a halo highlight around a node, such as node2910(H), can indicate its being considered true to explore what otherbeliefs are implicated and a similar highlight on an arc can illustratethe implication itself.

In the illustrated example, the galaxy visualization 2906 contains aplurality of points 2920, where each point represents a zoomed-out viewof a story visualization 2904 for a particular language problem. Throughthe animation of zooming out to the galaxy view 2906 and then back in tothe single story view 2904, one can see and learn how the system ispursuing the understanding of many language problems at once and thatthe visualization can change its focus.

CONCLUSION

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described. Rather,the specific features and acts are disclosed as exemplary forms ofimplementing the claims.

What is claimed is:
 1. A computer-implemented method, comprising:maintaining a collection of uninstantiated semantic structures in amemory of a computing system; receiving, by the computing system, anatural language input; performing, by the computing system, a syntacticanalysis of the natural language input to produce one or more linguisticanalysis results; instantiating one or more uninstantiated semanticstructures with natural language information from the one or morelinguistic analysis results to form one or more instantiated semanticstructures; creating, by the computing system, a semantic structure withthe one or more instantiated semantic structures to represent thenatural language input based at least in part on using the one or morelinguistic analysis results and knowledge induced from large languagecorpora, wherein the semantic structure includes multiple generativesemantic primitive (GSP) structures defined with roles that indicate oneor more beliefs regarding a first understanding of the natural languageinput, wherein defining the roles includes mapping one or more entitiesin the natural language information to the roles; generating, by thecomputing system, one or more structured questions to evaluate thesemantic structure and the one or more beliefs; maintaining a dependencystructure for linear dialogs to identify questions that are independentfrom one another; submitting, from the computing system to a separateuser computing device, the one or more structured questions forpresentation to a human user; receiving, by the computing system fromthe separate user computing device, one or more responses indicative ofinput from the human user when answering the one or more structuredquestions; and revising, by the computing system, the semantic structureto produce a modified semantic structure that includes a new GSPstructure defined with at least one new role that indicates a new beliefregarding a second understanding of the natural language input based atleast in part on the one or more responses received from the separateuser computing device, the modified semantic structure representing thenatural language input differently than how the semantic structurebefore revision represented the natural language input based at least inpart on the second understanding of the natural language input learnedfrom the human user.
 2. The computer-implemented method of claim 1,wherein receiving the natural language input comprises: receiving audiocontaining a verbal representation of the natural language input;generating an audio signal from the audio; and converting the audiosignal to the natural language input.
 3. The computer-implemented methodof claim 1, wherein the one or more linguistic analysis resultscomprises at least one of a syntactic parse, a predicate argumentstructure, an entity type, or co-references of the natural languageinput.
 4. The computer-implemented method of claim 1, wherein creatingthe semantic structure comprises: forming the multiple GSP structuresusing the one or more linguistic analysis results, data maintained in acurrent world model that expresses confidences in how accurately themultiple GSP structures represent the natural language input, and theknowledge induced from the large language corpora; and choosing one ormore of the multiple GSP structures to produce the semantic structure.5. The computer-implemented method of claim 1, wherein creating thesemantic structure comprises: determining a particular theme or aparticular context of the natural language input based at least in parton the one or more linguistic analysis results; and selecting the one ormore uninstantiated semantic structures from the collection ofuninstantiated semantic structures based at least in part on thecollection of uninstantiated semantic structures having an abovethreshold probability of being included with the semantic structure thatis associated with the particular theme or the particular context of thenatural language input.
 6. The computer-implemented method of claim 1,wherein submitting the one or more structured questions comprisessubmitting different ones of the one or more structured questions tomultiple user computing devices for presentations to different humanusers and iterating through the dependency structure based at least inpart on the different ones of the one or more structured questions toidentify a set of next questions.
 7. A computer-implemented method,comprising: parsing, by a computing system, a natural language story toproduce a syntactic representation of the natural language story;performing, by the computer system, a predicate argument structure (PAS)analysis on the syntactic representation of the natural language story;assigning, by the computer system, one or more entity types to one ormore words in the natural language story; determining, by the computersystem, co-reference chains in the one or more words in the naturallanguage story; inferring, by the computing system, one or more semanticstructures as a semantic representation of the natural language storyusing, at least in part, the syntactic representation of the naturallanguage story, the one or more semantic structures including generativesemantic primitive (GSP) structures defined with roles, wherein theinferring includes associating a semantic structure of the one or moresemantic structure with a particular theme or a particular context ofthe natural language story; engaging in multiple dialog sessions withcomputing devices of multiple human users in parallel, by generating andsubmitting one or more structured questions for presentation viacomputer user interface to the computing devices of the multiple humanusers, to receive responses from the multiple human users for use by thecomputing system to evaluate the one or more semantic structures as anunderstanding of the natural language story; and responsive to theresponses from the multiple human users, revising the one or moresemantic structures by defining at least one new GSP structure with atleast a new role for the semantic structure, the at least one new GSPstructure having an above threshold probability of being included in thesemantic structure associated with the particular theme or theparticular context of the natural language story.
 8. Thecomputer-implemented method of claim 7, wherein the syntacticrepresentation comprises at least one of a syntactic parse, a predicateargument structure, an entity type, or co-references of the naturallanguage story.
 9. The computer-implemented method of claim 7, whereinthe inferring comprises: retrieving, by the computing system, one ormore frame structures from a collection of frame structures in a memory,the one or more frame structures including one or more sets of GSPstructures defined with predicates and roles that are relevant to acurrent understanding of the natural language story; and aligning, bythe computing system, entities in the natural language story to theroles defined in the one or more sets of GSP structures for the one ormore frame structures.
 10. The computer-implemented method of claim 7,wherein the one or more semantic structures comprise the GSP structuresto facilitate inference at a sentential level and frame structurescomposed of multiple GSP structures to facilitate inference at athematic level.
 11. The computer-implemented method of claim 7, whereinengaging in the multiple dialog sessions comprises generating the one ormore structured questions to evaluate the one or more semanticstructures.
 12. The computer-implemented method of claim 11, whereingenerating the one or more structured questions comprises: building adependency structure that provides a dialog context for interpreting andanswering the one or more structured questions, the dependency structurebeing derived from data in the one or more semantic structures; andforming the one or more structured questions in a natural language. 13.The computer-implemented method of claim 12, wherein the dependencystructure comprises a tree-type data structure with root nodes andbranches to children nodes that can be logically traversed to askopening and follow-on questions.
 14. A computing system, comprising: adatastore containing a current world model that expresses beliefs abouthow natural language is understood; one or more processors; and memorycoupled to the one or more processors, the memory storingcomputer-executable modules comprising: a story parsing engine tosyntactically analyze a natural language story to produce linguisticanalysis results; a knowledge induction engine to induce informationfrom large language corpora to form induced information; a knowledgeintegration engine to form semantic structures that provide a semanticrepresentation of the natural language story, the knowledge integrationengine using the linguistic analysis results, information from thecurrent world model, and the induced information to form the semanticstructures, wherein the semantic structures include generative semanticprimitive (GSP) structures defined with a predicate and one or moreroles that indicate beliefs regarding an understanding of the naturallanguage story, the knowledge integration engine including beliefgeneration components to produce a probability distribution over a setof beliefs about the understanding of the natural language story; and adialog engine to facilitate a dialog session with a human user bygenerating and submitting one or more questions for presentation via acomputer user interface to a computing device used by the human user andcollecting one or more responses from the computing device indicative ofinput from the human user, wherein the dialog engine maintains adependency structure for linear dialogs to identify questions that areindependent from one another; and wherein the knowledge integrationengine revises the semantic structures by defining at least one new GSPstructure that indicates a new belief regarding the understanding of thenatural language story, the new belief having an above thresholdprobability of being relevant to the understanding of the naturallanguage story based at least in part on the one or more responses fromthe human user, and wherein the knowledge integration engine updates thecurrent world model in the datastore.
 15. The computing system of claim14, wherein the semantic structures further include frame structurescomposed of multiple GSP structures.
 16. The computing system of claim15, wherein the knowledge integration engine continues to revise thesemantic structures until a termination condition is reached, thetermination condition being a function of a confidence value that iscalculated to express an extent to which the frame structures fit thesemantic representation of the natural language story.
 17. The computingsystem of claim 14, wherein the knowledge induction engine comprises aword sense disambiguator to disambiguate word senses.
 18. The computingsystem of claim 14, wherein the knowledge integration engine comprises ajoint inference engine to calculate a marginal probability of eachbelief in the set of beliefs for use in constructing a story modelrepresentation of the natural language story.
 19. The computing systemof claim 14, further comprising: an additional datastore to store alibrary of uninstantiated GSP structures, the additional datastore beingpart of, or accessible by, the computing system; and a linguistic-to-GSPmapper module to select one or more uninstantiated GSP structures fromthe library of uninstantiated GSP structures in the additional datastoreand instantiate the one or more uninstantiated GSP structures withinformation from the linguistic analysis results.
 20. The computingsystem of claim 14, wherein the dialog engine facilitates multipledialog sessions with multiple human users concurrently.